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Encryption Privacy

Signal Launches Face-Blurring Tool as US Protesters Embrace Encrypted Messaging (venturebeat.com) 117

Law enforcement officials across the U.S. have already revealed that they will leverage facial recognition technology to retroactively target protesters following the killing of George Floyd, with police asking the public for footage and photos. Against this backdrop, Signal is introducing a new feature that can automatically obfuscate faces shared within the encrypted messaging app, as the company says it's "working hard to keep up with the increased traffic" from protesters. From a report: Moving forward, Signal users will be able to activate a feature in the main photo editing toolbox that will automatically blur all faces it identifies in an image. As with many automated computer vision tools, Signal doesn't claim that its face-blurring smarts are 100% effective. It may not identify all faces in a photo, which is why users can manually obscure faces by drawing the blur brush across each face with their finger.
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Signal Launches Face-Blurring Tool as US Protesters Embrace Encrypted Messaging

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  • That's a very clever move on Signal's part. Metadata about where people were when is very useful to a hostile government, and having that blurred out by default is absolutely the right move. Sure, the person you're talking to is identifiable, but keeping the 100 random people in the background anonymous is great.

    • by longk ( 2637033 )

      Blurring is nice. But it also has a honeypot effect. Signal was already popular with the people instigating the riots and it will now be more so.

      Signal still knows who chats with who, even if the content is encrypted. That's info authorities can get there hands on, even if it's after the fact.

      The first step to rolling up a organization is to identify who talks to who, when and it what order. It identifies players, hierarchy and priority for further investigation.

      I know from experience that OS funded NGO's h

      • Re:Very clever (Score:4, Interesting)

        by dgatwood ( 11270 ) on Thursday June 04, 2020 @12:47PM (#60145392) Homepage Journal

        Blurring is also mostly useless, at least for video, because the moving image makes it possible to largely recover the original image. I can't find the original paper I read about this a decade or more ago, but the gist of it is that because the data is manipulated in a well-understood way, you can use multiple slightly different images to approximately recover the original data. Also, there was this paper involving machine learning and image recognition of highly pixelated images [wired.com].

        • by lgw ( 121541 )

          You guy are basically saying "it's not perfect so it's useless". Security does not work that way. Security is not binary. Each and every little thing that makes it harder for the bad guys is a good thing! The more resources an attacker must spend for each bit of data they want, the less they get in total. Everyone has fixed resources to work wth.

          • by dgatwood ( 11270 )

            But the thing is, putting a black box over the face is 100% effective at preventing identification of the face. Why do something computationally expensive and fairly easy to defeat when there's an alternative that is computationally almost free and robust?

        • by Nite_Hawk ( 1304 )

          I don't think a prosecutor saying "We took all of these blurred frames from a video and had a (proprietary) computer AI look at them and come up with an image that approximately looks like the defendant!" is going to fly as evidence in court. If it does, we are screwed anyway.

          • by Shotgun ( 30919 )

            That's not evidence for a conviction. That is evidence for a warrant. A warrant for a search, arrest and questioning.

        • by pjt33 ( 739471 )

          You don't even really need video: find the convolution matrix, invert it, convolve. The benefit of video is that you can essentially see different frames as giving different subpixels of a higher resolution image.

        • I bet at some point that they will be able to create a 3D model of somebody's face from a person's shadow, with enough video frames providing enough angles. Then be able to cross reference that with a model built up from other image and video sources. It's just a matter of time for people to supply and tag enough content of themselves and other well maintained data sources and for data processing capabilities to catch up.

    • By "hostile governments" you mean the Democrat mayors and Democrat police chiefs?
      • by lgw ( 121541 )

        Eh, this week they're Democrats. Next week who knows? That's the entire founding principle of America: don't trust the government more than you have to, because everyone turns on you eventually, in the fullness of time.

        Each little thing we can do to claw back a bit of liberty or at least anonymity is a good thing.

  • By "protestors" you mean Antifa and White Nationalist groups, right? Because the rest of us don't hide our faces and are proud to march in protest.

  • Protests? (Score:5, Insightful)

    by onyxruby ( 118189 ) <[ten.tsacmoc] [ta] [yburxyno]> on Thursday June 04, 2020 @11:59AM (#60145176)

    Those are rioters, not protesters. Protesters donâ(TM)t do things like loot, riot, commit arson and burn down hundreds houses and businesses (sometimes with people still in them), and then keep the fire department away, throws rocks and fireworks at people, bricks and Molotov cocktails at cars (sometimes with people still in them) and motorcycles, attack bystanders on the street and beat them severely and ambush and kill people.

    Letâ(TM)s just say you donâ(TM)t see very many protest signs at these protests. Sure there are some protests in the day hours, but the majority of whatâ(TM)s going on is are riots that are cover for a massive crime wave targeting retailers and in particular luxury stores.

    • Re: (Score:3, Insightful)

      by Anonymous Coward

      Let’s just say you don’t see very many protest signs at these protests.

      Of course you don't. The original protesters achieved their goal: getting four cops fired because one of them used a choke hold against an intoxicated man who was resisting arrest who then later died while still technically in police custody. Job done. Then they moved the goal posts to be criminal charges, and that happened too. Job done. Then they moved it yet again to be murder charges, and that also happened. So, yet again, job done.

      What's the new goal? There isn't any. There are no demands. There's noth

      • Re: (Score:3, Informative)

        by Anonymous Coward

        What's the new goal? There isn't any. There are no demands..

        Accountability. It shouldn't take a huge worldwide protest every time a cop does something like that to be held accountable.

        Also, in NY there are calls to [changethenypd.org] repeal [innocenceproject.org] 50-a [brooklynnaacp.org]

      • by AmiMoJo ( 196126 )

        The goal is the same as it has always been: end systemic police violence against black people.

        This keeps happening. It's not just this one time, it's something that happens over and over. That's what they want to see an end to.

        • Sure. We would all like to see it end. Even the most ardent police supporter I know (has police in his family) was condemning the killing of Floyd and some other recent incidents in with very strong language. But the problem is that we have around 800K police in the USA, and they are just ordinary people. 1. Very few places have the know how and resources to properly screen candidates for mental and emotional disposition. Because they are just people, some that are not suited to the job are going to make it

      • four cops fired because one of them used a choke hold against an intoxicated man who was resisting arrest who then later died while still technically in police custody.

        Four cops fired because three of them sat on top of a handcuffed man that was begging for his life until he passed out while one of them put his knee on his neck for almost 8 minutes even after that man stopped being responsive.

        And all this because of the suspicion that he used a fake $20 bill. They even pointed a gun at him while he was still sitting in his car.

        Superb police work.

      • "The original protesters achieved their goal: getting four cops fired"

        OK Ivan.

        The goal was not to get cops fired. The goal is to signal unwillingness to tolerate further injustice.

        Your anonymous, cowardly attempt to reframe the protests fails.

      • "died while still technically in police custody"? You are one sick mother fucker.

      • by yarbo ( 626329 )

        I was at my local protests and the reasons signs decreased as the days went on because they were dropped when people ran from pepper balls, tear gas, rubber bullets, and other forms of police violence. Signs reduce mobility.

        There are a spectrum of protestors with some advocating for increased accountability (no, firing people for using a painful compliance hold prohibited due to its danger is not the goal, appropriate criminal charges was), some for demilitarization, and some for an elimination of police d

      • because one of them used a choke hold against an intoxicated man

        For eight minutes while he lay in the street handcuffed and held down by two officers, including two minutes after his heart stopped

        who was resisting arrest

        Like hell he was. Did you even see the video?

        who then later died while still technically in police custody

        If lying in the street with some thug's knee on his throat constitues "police custody".

  • Are they automatically blurring the faces of the people who set fire to things, loot buildings, smash windows, and attack innocent people? It seems like they are on the wrong side of this/
    • by PPH ( 736903 )

      Are they automatically blurring the faces of the people who set fire to things

      I'm sure Signal has implemented AI to determine the motivations and moral beliefs of each person photographed. And will only blur the images of those that meet the highest standards.

  • by liquid_schwartz ( 530085 ) on Thursday June 04, 2020 @12:30PM (#60145336)
    Protesters are peaceful and have no cause to be arrested. Looters steal, rioters start fires, break and vandalize, and generally cause trouble. Protecting looters and rioters is bad policy.
    • by Anonymous Coward

      *shouldn't have cause to be arrested, or beaten, or shot at

      Like the journalists who had "nothing to fear".

      Protecting people from the bullshit in the middle line of this post is good policy. We've known "Nothing to fear" is bad policy, dating back much much longer than this current mess of factions.

      • I hear you that nothing to fear isn't perfect, but deliberately protecting rioters and looters seems like even worse policy. So far we've seen that people talk big about supporting riots until the riots get near them, then they change their tune like this guy https://districtherald.com/you... [districtherald.com]
  • If you blur it consistently, the AI may still be able to recognize the patterns. Just train it with pre-blurred images.

  • by ZoomieDood ( 778915 ) on Thursday June 04, 2020 @12:55PM (#60145438)

    There's a BIG difference between protesters and people involved with criminal activities (vandalism, looting, assault, obstruction of justice or first responders).

    Why is Signal sullying their name to protect such people? If they're so willing to be photographed and videod doing peaceful protests, then what do they have to hide?

    I get the need to protest to enact change. I have YET to find a justification for the rampant violence and criminal activity that is occurring.

    • by AmiMoJo ( 196126 )

      I suppose you think Apple and Google are sullying their names by supplying uncrackable phones to criminals too. I can't imagine what you think of Tor and GPG.

      • Are they framing it as support for the riots
      • I'm a BIG privacy advocate! And there are indeed good reasons for preserving it for the general populace, key above all - most people with a little authority abuse it.

        In this case, it's hard to justify ongoing preservation of anonymity in the face of illegal actions.

        Perhaps a better way would be to have the ability to "undo" the anonymity through the use of trustworthy screeners who will determine if there is an act of vandalism, looting, etc. that is being obscured, and if that's not the case, maintain th

    • by alvinrod ( 889928 ) on Thursday June 04, 2020 @02:09PM (#60145800)
      Does Signal have a magical oracle that can determine who is a peaceful protester and who is engaging in criminal activity? Of course not and while it's easy to claim that it's just a way to protect the people who are committing crimes, it can also be used to protect the innocent as well. Would you really trust the police to never have a case of mistaken identity that leads to a wrongful arrest? Of course not, so even peaceful protesters have a really good case for using this.

      It's practically the same argument that people make against the fifth amendment. James Duane's excellent video Don't Talk to the Police [youtube.com] provides excellent examples of why people who are completely innocent should still use their fifth amendment rights. Did the founding fathers want to sully their names in order to protect criminals? Hardly. They realized that as bad as criminals might be, the state and its monopoly on violence can be far, far worse.

      I hope the looters and agitators can eventually be brought to justice and that they will pay any debt to society that they owe for their crimes, but I don't see why we should give up our rights and bend over backwards to make it easier for the state to prosecute us. Take a step back and imagine if Signal were doing this in response to the protests in Hong Kong against the CCP who claim those protestors are engaging in criminal acts. Did you opinion about the morality of this decision change at all?
      • You have good and valid points! I've been at the receiving end of police lies about my activities, and they fought it (by trying to intimidate me) until 2 hours before court time, and they dropped the case. I was going to use THEIR video against themselves (because I *WAS* innocent).

        Imagine the loss of evidence by blurring your own photo showing innocence.

        And this picture anonymization is going to be pointless to some degree anyway, when everyone's cell phone is giving them away when they're in a curfew-

    • by yarbo ( 626329 )

      > Why is Signal sullying their name to protect such people?

      Have you ever heard a talk by Moxie Marlinspike? This is completely in character and in line with his work and messaging which is why I switched from iPhone to a Galaxy Nexus back in the day to run RedPhone and TextSecure.

      Why are the police sullying their name by covering up their name tags and body cams while they engage in actual violence and criminal activity?

      • THIS is a good point! Policies should be changed so that ANY police action MUST be recorded, or disciplinary actions happen. It protects both sides from allegations of wrongdoing. And THIS is what BLM should be agitating for if they really believe that they're being discriminated against by police.

  • How about instead of blurring the faces of protesters they face swap them with the faces of politicians?

  • If you look at the pics in TFA [venturebeat.com], the blurred areas are not uniform. They seem to generally follow the underlying color gradient.

    Unless this is done using a Gaussian (random) blur, this is the WRONG way to do it. If the blur is done using a non-random algorithm (like averaging with nearest neighbor pixels), the process is reversible. Even though the rectangle looks blurry, with the color data in the blurred rectangle plus the color data of the surrounding non-blurred adjacent pixels, you can reverse the [ox.ac.uk]
  • So what if Signal blurs your face. There are people all around, all taking their own pictures with their own phones and apps. The police won't need images from Signal!

  • Cops arrested, will be tried. Stop the protests so we can concentrate on the criminals. The trained antifa criminals.

  • There are protests, there are riots. I am white and I respect my African-American peers enough not even to try to say I understand what they are going through. Peaceful protest would be ideal if: 1. it would be heard. If there were enough instances where peaceful protest actually made a difference. 2. if the protesters were not angry, or far-far beyond angry. I know rioting, violence, looting, etc. are not the answers and they can end up hurting the very people who's lives we should be trying to protect. B

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