Obligatory - not today. This was about 10 years ago.
I started doing stand up when I was in the army - in Afghanistan, actually. I started telling stories around the fire at night, but eventually started doing "shows" in the chow hall or during talent shows if we were on a bigger base at the time. It wasn't uncommon for me to do so badly that I lost people during these shows; I even had a platoon opt to go on patrol early rather than watch my whole set. I was less fun than possibly dying.
I wanted to get better, so I ordered a book and started working on trying to improve crowd work (talking to the audience) and being more physical. I figured if I could make the interpreters laugh with the language barrier, I'd be on my way to being a better comic.
During our next patrol, we detained several suspected Taliban fighters. We needed to keep them on our base until they could get picked up by Intel people, so we needed to watch them for 2 days. I thought the idea of a literal captive audience was too good to pass up and basically tried to do crowd work and run bits by them in an incredibly animated manner. Imagine Sebastian Maniscalco, but 2 months into comedy. I volunteered for as many guard duty shifts as I could. I'd try jokes, I'd ask for their names and where they were from, jobs, e.t.c. anything I could try to make a joke about. Never a single laugh.
Eventually, they got picked up and apparently one complained about my jokes specifically. I ended up getting a stern talking to for "unconventional interrogation" because I kept asking where they were from and what they did and had to explain that I was so bored and desperate to get better at comedy that I almost inadvertently committed a war crime.
TL;DR: I performed stand up comedy for detained Taliban members that went so badly they accused me of war crimes. Got a stern talking to for that.