How do you deal with Hacked forums/Usernames?

I had many hacked usernames, how would you deal with it?

 

I would change the emails and passwords of the hacked usernames on my forums, and warn the members that the certain account was hacked. I'd then try to find the orginal person who owns the account so that I can return the account back to him/her.

 

Contact the original owner that their account has been compromised and reset their details for them