You could be in this FBI facial-recognition system and not even know it

Whenever you upload a photo of yourself or your friends to Facebook, the social network uses a facial-recognition algorithm to identify who's in the picture -- and then suggests that you tag them. This might strike some as a little creepy, but at least it's relatively transparent. The same may not be true of a massive facial-recognition setup used by the FBI, which not only combs through pictures of criminals but also allows law enforcement to search the faces of millions of other law-abiding citizens without their knowledge. And now a top federal watchdog says the program risks putting countless Americans under needless suspicion because of the system's lack of safeguards. The FBI has access to more than 410 million photographs of people's faces.