There's a town called Penistone and the Scunthorpe is famous less for its football team, than for tripping off poorly coded censor scripts. Generally there's a need to look at the broader context before acting.
With respect to users called Admin - if there's no practical risk of impersonation, it's not really a big issue.
Practically - it's not a great idea to try to try to moderate language by filters, and honestly if we wanted to start policing profiles, there's a few thousand spammers I'd love to have the time/energy to take care of.
While I do agree a good many of these usernames (but not all!) don't belong here, honestly I don't think it's a practical thing to look through, classify (as innocent or offensive) and reset/moderator message every user who might be so now and in future. There's also no great tools to deal with profiles in general.
If you see a post with an offensive username, flag it - the moderators will deal with it. If a user is trying to pass himself off as a moderator or other person of some degree of authority, once again, flag it. We can deal with those fairly effectively.
There's discussions of similar issues here and that's a useful starting place to start.