You should read Hendrik Smith's "The Russians". When he buys an ice cream cone in a park, he buys 2 and passes one behind his back for his unseen and unknown "tail" to eat. This was in the late Soviet era so everyone knew it was just a game anyways.
Arlo Guthrie was for a time under FBI surveillance for his work against the Vietnam war. He was able to get discount airfare at the time, as youth fares were available for unsold seats right before departure. He had a great story about going to the airport, and finding the FBI tail had booked the last seat on a plane. Since Arlo couldn't buy a ticket, the agent had to wait. So he had a dilemma. If he cancelled the seat, Arlo could buy it and leave without him. If he got on the plane, he would have to hope to catch up after whatever flight Arlo managed (if he didn't change destinations).
Also during the Vietnam war, my father was part of a peace movement group at Portland State that helped with deferments and CO forms. Being a poor student group, at one point they couldn't pay the phone bill. But the phone never got turned off. As far as they could tell, the FBI didn't want to lose the phone tap, so they took over the payments. Once they figured out the phone wasn't going away, they invited anyone that wanted to use the phone for long distance calls.