My website occasionally receives requests from users asking for their account to be deleted. The website itself is a dating site that stores messages between users, personal information they add to their public profile, logs and stats about their usage, etc.
While the site currently lets an admin 'deactivate' a user's account such that it no longer appears publicly, actually deleting the user record and its associated data from the database is problematic. Information we'd be deleting about a user is occasionally necessary and always useful.
One alternative I have toyed with would be to attempt to anonymize the user by clearing all personally identifying pieces of information. Reading about the de-anonymization that occurred with the Netflix dump, it looks as though this could be quite hard to do effectively.
Should I have to comply with this request, legally or otherwise? ie. does the site need to have functionality that allows us to completely delete all traces of a user? Would attempting to anonymise a user be sufficient? I understand Facebook allow for your account to be 'deleted', but do their really remove all traces?