How to all any and all characters in usernames

Hi
I've found some members complaining that they can not register a new account using different characters like !@#$%^&*()_+|
How to enable such a thing because each time they try to register they get an error [code]The user name contains an illegal character.[/code]
Note: I've did not found any module to do this job and also the topics mentioned on the forum for this regards did not solved the problem at all yet.
Please advice how to allow different and all characters in user names.
Thanks