Granted this could also be done with a Word Doc or notepad, but essentially someone with less-than-honorable intentions could use it to maintain dossiers on posters and piece together enough details to get their real life identities (I'm sure I have divulged more than enough that people could identify me if they were keeping tabs). Then you have the potential of idiots sabotaging real lives like certain yewts did on more than one occasion with Y'z Guy (causing problems with employers, crashing weddings, etc). It probably would not happen often, but that it happens at all could be a problem.