I was in a mostly abandoned industrial site practicing parkour with a friend of mine. It was dark out and we assumed that no one would see us, or if they did, no one would really care. Turns out there was a pregnant woman working late in the office building accross the street who somehow heard us and called the cops. The entire police force came (cops in my county have nothing to do), saw us in our parkour getup (mostly black clothes), undoubtably thought we were burglars (come to steal god knows what, shingles from the roof of an abandoned building?) and promptly arrested us.
I, along with my friend, had do 50 hours community service and serve 6 months attending a "juvenile rehabilitation program". We were 15 years old. Besides us, the program consisted of: two drug dealers, a teen prostitute, an autistic 12 year-old kid who had threatened to kill several of his schoolmates, and some random guy from my school who I recognized but who made an obvious effort to ignore the fact that he knew me. Needless to say, my friend and I felt decidedly out of place in the group.
This was only hightened by the climactic conclusion of the program. We took a field trip to the San Quentin California State Prison were we got to meet a few inmates (including some death row inmates, I kid you not). We all were assigned a "buddy", every one of them convicted of murder, manslaughter, or aggravated assault, etc.. Mine was a charming 6'6" or so 240 lbs beefcake black man who was convicted of some form of murder. This was, in fact, his second murder: He had previously killed a man in a robbery and the day he was let out of prison for that crime he then killed another man for looking at his girl or some equally clichéd testoste-rage. I remember most of this becuse, quite simply, this event was far too traumatic to forget. I mean, seriously?
The giant murder-hulk and I talked for a little bit. Mostly this consisted of him telling me his life story and me trying not to shit my pants. After saying how beneficial the program I was in and how- if he had the same opportunity- it would have helped him to avoid a later life of crime, he asked me what I did that got me put in the program to begin with. When I told him, he couldn't believe me. He asked me if I was absolutely sure that I wasn't trying to steal something or if I was lying to him. When he finally accepted that what I told him was true, we just sat there in awkward silence. Then we talked about the food at the prison cafeteria (we had just had lunch). I never figured ou how he could stay so buff when all they had for lunch was a flimsly balogna sandwich, an apple, and a cookie... that still haunts me to this day.
TL;DR: Basically the plot of mirror's edge except the fascist police caught me. I was doing parkour on unused, abandoned property. The entire county police department came and I was arrested so it didn't look like they sent the whole force out for nothing. I didn't resist arrest or run away (although I should have).
Can you even call it tresspassing if the site's been abandoned for years?
Would I do it again? The parkour, yes. The arrest and subsequent sentence, not if I could help it.
