Dozens of times a day, no doubt. It would be foolish for an innocent witness to a murder, for example, to avoid talking to police because he thinks he's going to implicate himself in something.

Anyone see the following happening in real life?

Officer: "So tell me what you saw."
Innocent witness: "Well, it was 3am and I was in a rush to get home after work. As I turned right on to 4th Avenue from Main Street...."
Officer: "Wait a minute. You said you turned right on to 4th Avenue from Main Street. That's a no-right-turns-allowed intersection. Here's a ticket for that, but please, continue."

Overactive imagination I suppose.