safe. i've heard of some Thugs (cowards) shooting people for not having money in their wallets when they get ganked.
More than likely they were just out to harrass, but you did the good things canceling your cards and what not. I would aslo pull a credit report later on too see if they are trying to steal your identity....probably not but you never know. and hopefullly you probably wont ever see them again and they just threw away your stuff