ctwxman writes "If you're running a recent vintage version of Windows, and connecting to the Internet with an IP address reachable from the outside world, you've probably seen them. They're rectangular boxes that pop-up out of the blue with advertising. These aren't pop-up (or pop-under) browser ads but actually a weird misuse of Windows Messenger Service, a mostly useless tool which Microsoft has left on by default! Though similarly named, this isn't at all related to Microsoft's IM product. You can't block these pop-ups by shutting down ports, because Windows Messenger Service shares some ports with other useful services. The best way to stop the pop-ups requires the user to readjust some internal Windows settings. As you might imagine, many users are reticent to do that. Now, AOL has come up with another solution. They're going into subscribers' machines, without asking and making the adjustments themselves! Though the short term result will probably be good, there are all sorts of implications when your ISP just reaches out and decides how your PC should be configured without your knowledge." The Computer Fraud and Abuse Act makes this clearly illegal; if this were a 17-year-old instead of AOL, the FBI would be investigating.