FWIW, I worked in the only phone company, Bell System, in the 1960s to get through school. They had the capability then to listen on any phone call without being detected, and at the time, they used it on guys who made sick phone calls to women and talked dirty. A little old lady with glasses sat in our unit with headphones on and a steno pad making transcript notes for the eventual prosecution. But our boss, who was a family friend, told us that the government needed a warrant before the phone company would turn over its records. They would sometimes get a warrant to listen in on criminal activities and national security threats, even then, when hippies were wanting to blow up the Capitol over the Vietnam war.
Like you, I hate the thought of an innocent person being mixed up in an investigation through error. But given the threat of jihad, on top of our virulent left wing in this country, it's just another front in the culture wars. It's always a trade-off between complete independence and security. Freedom isn't free.