I volunteered at a bike co-op for a while. All bikes at the co-op were donated, and were fixed by volunteers to be sold to keep the lights on, but just barely, OR (more often) volunteers would work a certain number of hours and earn a bike, with no money changing hands. When bikes first came in, the seatpost, stem, and bottom bracket were checked to ensure they weren't seized, and the bike was given a very quick once-over to ensure there was nothing else that would make the bike unfixable or unsafe like a cracked frame or fork. Then the useable bikes were moved to another room to await a full rebuild by volunteers, and the unusable were stripped of any usable parts and put into the 'discard' pile to await transport to the metal recycler.
One evening a chap comes in, I can't remember what for, and sees a ruined bike in the 'discard' pile that he claimed was his. He started ranting about how we were running a 'chop shop' and that he was calling the police. A couple of us regular volunteers politely tried to calm him down, said go ahead and call the police because we have nothing to hide and then we can straighten this out. We tried to explain that the shop was non-profit and it's mandate was to provide bikes to people on low incomes, but he kept ranting.
Then a middle aged lady who was volunteering, fixing an old bike, leaned over to me and said "I've dealt with people like this before, I'll show you how to handle it".
She walked right up to the angry guy and pointed to the door.
Lady: "OUT!"
Angry Guy: "This is a chop sh..."
Lady: "OUT!"
Angry Guy: "I'm coming back wi..."
Lady: "OUT!"
Angry Guy: "You ar..."
Lady: "OUT!"
Angry Guy: "I..."
Lady: "OUT!"
Then the angry guy turned and walked out the door. We went back to fixing the old bikes. Never heard back from the angry guy again.