So there are government agents sitting through millions and millions of mundane phone conversations every day hoping to hear someone say something significant?
"We're having lasagna"
"Oh, really? Should I pick up a loaf of bread?"
"Yes. Get some bread and get me some Diet Pepsi too, babe. Use the debit card, not the credit card, O.K.?"
"OK, I know, I know. See you when I get home."
Exciting life in law enforcement, huh?