I run an online service that has been going since 1998. There are lots of instances of abusive behaviour there. We have a whole range of ways to deal with these and we feel that as long as users operate within the terms of service that they have a right to participate. Selectively withholding access for capricious reasons would be discriminatory behaviour. On top of that you never know how big a role your free service plays in someone else's life. Banning users / deleting content is a decision that you should not take lightly as a service provider.
