yeah, twice. I live in a university town, so the cops here are usually too worried about drunk underage kids to pull over bikes.
I pulled a 90 turn onto a sidewalk that runs between two buildings at about 1am, actually going to one of the bildings to do some work, all lit up front, back, and helmet. Cop was on foot and shouted "hold on there son" and shone his mag-lite on me. I stopped and dismounted and explained myself, and he was cool about it and said "at least you've got all the other stuff to make you legal for the road". but he told me never to ride down there again. Which of course I have, every day since.
I also ran a red and got pulled. I was making a left and actually stopped and waited through 2 cycles, but finally just figured '**** it, I'll just yield on green next time around' and did, but I didn't get 100 yards on the other side before I was pulled. Still don't know where the cop came from, but I didn't have a front light yet because my bike had been stolen the week before and I hadn't gotten all the stuff for the 'new' on yet.
I got a 10 minute lecture, but lots of 'yes sir, no sir' and I got off. I break so many traffic laws that i'm surprised I haven't actually been ticketed, but now I scan before doing anything blatant.