The brilliant Fairfax County Fuzz in my area pulled a boneheaded manuver a few years ago.
Roadblock. After dark. Residential street. Approaching it, all the flashing lights made me think there was a car crash or something. I stopped, trying to see whether the road was open or blocked. A cop motioned me to come forward. Well, gotta obey those copper hand signals, far as I know. So, I drove forward half a block or so to the cop. Who then handed me a handbill, said there had been a very serious crime recently in the area, and asked if I had seen anything unusual.
WTF!! I was involuntarily seized in a roadblock to ask my voluntary cooperation in an investigation!?! Huh?
What were those people smoking?