METADATA IS MORE INTRUSIVE! REPEAT: METADATA IS MORE INTRUSIVE!

[Maedhros]

64. This is an explanation:

"For example, she said, in the world of business, a pattern of phone calls from key executives can reveal impending corporate takeovers. Personal phone calls can also reveal sensitive medical information: “You can see a call to a gynecologist, and then a call to an oncologist, and then a call to close family members.” And information from cell-phone towers can reveal the caller’s location. Metadata, she pointed out, can be so revelatory about whom reporters talk to in order to get sensitive stories that it can make more traditional tools in leak investigations, like search warrants and subpoenas, look quaint. “You can see the sources,” she said. When the F.B.I. obtains such records from news agencies, the Attorney General is required to sign off on each invasion of privacy. When the N.S.A. sweeps up millions of records a minute, it’s unclear if any such brakes are applied. "

You may not like the explanation, but it's right there.