Most landlords consider it routine to re-key the locks before renting an apartment to a new tenant.
However, this isn't always the case. Bob had moved out of the apartment, and Joe still had a key. Well, one night, Joe partied a little too hard, and, knowing Bob wouldn't mind if he spent the night at the apartment, Joe went on over. It was really late at night, so Joe crept in quietly and made it back to the guest bedroom without saying hello. In the morning, Joe woke up to hear the voices of several women in the living room.