I've done some accidental, clumsy things, like stepping on paws or dropping something in the kitchen on or near the kitty, but the only thing I did that really upset me (and still gives me a sick feeling in my stomach to think about) was when I was pregnant with my daughter and getting her nursery ready. We had a lovely girl kitty who was about 2 years old, and she naturally thought we had put that crib in that room just for her. We also had this quilted sling-like contraption in the crib (to make it into a mini-bassinet type thing), which the kitty LOVED to lay in. Now, I think when you're pregnant, you just generally get crazy and hyper anyway, and I thought I'd better dissuade the kitty from getting up in that crib once the baby was here, because I'd heard all those ridiculous tales of babies being killed by cats sleeping on their faces, etc. So when I found her in the "nest" one day, I picked her up out of there and proceeded to give her a "Joan Crawford-style" spanking and yelling, so that she would forever associate the crib with something unpleasant. Well, it worked - she not only wouldn't go anywhere near the crib, but wouldn't go anywhere near our daughter either. I have never to this day forgiven myself for that, and hopefully my kitty at the RB has found it in her big kitty heart to forgive me.