It's only a bill at this stage, and there's no certainty that it'll survive both Congress and the President's desk. The proposed law certainly has its share of privacy concerns. Although it would force criminals to scrounge for alternatives (such as stolen phones or meeting in person), it'd also make it virtually impossible to buy a burner simply because you're concerned about sharing personal information. As it stands, disposable handsets are only one part of the security picture -- as the fight between Apple and the FBI has shown, it's sometimes the data on the phone that matters.