The American Civil Liberties Union (ACLU) compiled and released a map of where the federal government is currently taking Apple, Google -- and in some cases, both -- to court in order to compel the companies to unlock a suspect's phone. There are reportedly 70 cases in which federal prosecutors have invoked the All Writs Act, according to court records from October. The ACLU managed to turn up 63 of them -- nine of which targeted Google; the rest, Apple.
Not all of these procedings involve the same issue as the recent Apple-FBI court battle over the San Bernardino shooter's phone. In some cases, the companies have complied with the warrant (that is, the phone wasn't encrypted or anything), however it should be noted that the Feds leveraged the All Writs Act, a statute they claim is used only as a measure of last resort, in every single one of these cases. Not unlike how they've managed to exploit PATRIOT Act provisions in the War on Drugs.