It's a netiquette pet peeve when people tag friends in photos that the person is not in. In my latest Poked column, I address this tacky trend and the reasons why you're annoying your friends.
But it's more than just irritating to someone who is picky about their profile image. Facebook often uses images of you as a security test to verify a friend's account.
Someone once tagged me in a photo of a coffee cup as a way of saying, "Hey, remember those good 'ole days at the college coffee shop?" It's possible that one of my friends will be asked if that coffee cup is me. Now they have to use a skip and possibly will be locked out of the account.
If you want to get someone's attention, just send a message. Photo tagging is not the way to go about it.