Samuel Gibbs, reporting for The Guardian: Hackers have again demonstrated that no matter how many security precautions someone takes, all a hacker needs to track their location and snoop on their phone calls and texts is their phone number. The hack, first demonstrated by German security researcher Karsten Nohl in 2014 at a hacker convention in Hamburg, has been shown to still be active by Nohl over a year later for CBS's 60 Minutes. The hack uses the network interchange service called Signalling System No. 7 (SS7), also known as C7 in the UK or CCSS7 in the US, which acts as a broker between mobile phone networks. When calls or text messages are made across networks SS7 handles details such as number translation, SMS transfer, billing and other back-end duties that connect one network or caller to another. By hacking into or otherwise gaining access to the SS7 system, an attacker can track a person's location based on mobile phone mast triangulation, read their sent and received text messages, and log, record and listen into their phone calls, simply by using their phone number as an identifier.Also from the report, "60 Minutes contacted the cellular phone trade association to ask about attacks on the SS7 network. They acknowledged there have been reports of security breaches abroad, but assured us that all U.S. cellphone networks were secure." Update: 04/18 16:51 GMT by M :Reader blottsie writes: U.S. Rep. Ted Lieu (D-Cali.) on Monday called for a full congressional investigation into the aforementioned widespread flaw in global phone networks.