There have been a few close ones (and one bust).
First close one: I was toking with a buddy near some halfbuilt houses down the road from me. We were lighting with matches and only had a few left and didn't want to use them up providing light for packing my bowl. So we step into some shadows near a streetlight. It was autumn at the time, and rather cold, so we were both wearing hoodies and ski caps and gloves, almost entirely in black. Someone across the street glimpsed us and thought we were burglars. A cop pulled up, no lights, engine off. He steps out right as I'm about to light it and I hear his footstep in the leaves. I drop everything and he hears it fall. He turns and sees it's two kids just chilling out under a streetlight and says he had a burglary call. We laugh about the absurd situation with the cop(while shaking and high as fuck). Then he leaves.

Second: My friend is driving me and a few other kids to an abandoned incinerator where we were planning on smoking. Suddenly, flashing lights behind us! The road was very narrow and winding with no shoulder, so my friend drives for about a minute until we reach a parking lot and pulls over. The cop is pissed about this when he comes up to the window. He asks for a driver's license. While my friend gets hers out I ask what we did. "Are you driving?", is the response. This of course confuses all of us. When I say nothing, he repeats the question. I say "Obviously not." This is obviously the wrong answer. Everyone is ordered out of the car. We get out and he makes us wait a few feet away. He picks up my friend's license, which had been loose in her glove compartment and was covered in white and blue chalkdust (don't ask why, stoned madness should be enough). The cop finds the white dust suspicious, so he gets his finger nice and wet, picks up some powder, and eats it. It seems he's eaten chalk before, because he immediately identifies it as such. He asks for a search, which we deny him. He makes no comment. Then he asks where we're going. My friend, being the idiot he is, tells him the road.There is nothing other than a few abandoned buildings and some empty lots are on the road with our destination. Once again no comment from the cop. He sets my friend's license on the roof of her car, then without speaking to us more, he drives away. We once again were very confused.