We've all gotten the notifications, "So and so has tagged you in a photo", pictures that you never thought you would see online or you just happened to be in the shot. It's essentially harmless socializing, but it can become irritating and unwanted if allowed to run-a-muck. Especially for individuals who are caught in embarrassing situations, regardless of the rest of their lives.
For the most part Facebookers demonstrate etiquette when posting content of others. But not everyone abide by the same level of courtesy so Facebook allows for users to remove their tag from a photo, also the option to customize security settings to some extent.
The biggest danger regarding photo tagging currently is due to the rise in popularity of employers asking potential employees for their Facebook log-in information, in this case a couple of high school pictures posted by someone the applicant hasn't seen in years could cast a negative light on the applicant and be enough to cost him/her the job. In a more mundane scenario, someone could find themselves in hot water if an incriminating photo entered circulation, for example, pictures from the movies taken when the person was supposed to be studying.
With the securities Facebook has implemented so far, and the common sense factor of etiquette, the possibility of trouble can still arise from photos. Perhaps an addition security settings that a tagger must have approval from the taggy before their name or whatever can be published.