I've had to turn my laptop on. Got the backroom swab once when the battery had died.

Few years ago I also got a serious camera inspection at DFW. This is the only time this ever happened to me. I had several rolls of film and two cameras, one of which still had a partially used roll in it. TSO pulled me aside, opened each film canister (black opaque ones) and took out the roll of film Then he opened the first camera (no film inside). When he started to open the second one, I protested - he'd ruin my film. So he took a picture instead and let me pass.