Technology changes quickly. Maybe even faster than the FBI. Internal documents suggest:
The FBI fears, for example, that 4G will require agencies to “deal with significantly higher data rates than in current wireless network intercepts,” according to the document. “Managing this ‘fire hose’ of data is complicated by the lack of buffering or reliable delivery requirements. … These higher data rates could place a greater emphasis on the filtering of data to identify specific content.”
To intercept VoIP, or voice-over IP traffic, in this environment, “voice packets will need to be extracted from the packet stream in near real-time,” the document states.