Federal agencies have largely kept quiet about these capabilities, but court documents and interviews with people involved in the programs provide new details about the hacking tools, including spyware delivered to computers and phones through email or Web links—techniques more commonly associated with attacks by criminals.
People familiar with the Federal Bureau of Investigation's programs say that the use of hacking tools under court orders has grown as agents seek to keep up with suspects who use new communications technology, including some types of online chat and encryption tools. The use of such communications, which can't be wiretapped like a phone, is called "going dark" among law enforcement....
