LOL, I was asked by a pet shelter for my SSN in order to adopt a cat. I stupidly put it down on the paper form and then asked why they needed it. She didn't have an answer and rejected my application to adopt. But she kept the paper form in case I tried to reapply in the future. I ripped it out of her hands and left. I should have just put a phony one in there...
They asked if I was going to let the cat outside. At the time we had another cat we adopted from a vet and we let it outside so it made sense that we'd let this one out too. That was a hard no (although they didn't tell you that). It was basically a trick question and if you didn't answer to their liking, they rejected you. That was 20 years ago. Nowadays the cat I do have is kept indoors at all times.