MySql LIKE

Why wouldn't you just choose a different escape character, and what's wrong with the default backslash? Do you really allow usernames to have a backslash as a valid character?

Because I use CI their query builder and they use '!' by default, nothing much I can do about it.

And that won't help me either, like I said I can't controll what characters are aloud and the source I am getting all the info from accepts all characters (even foreign language characters, was a pain in the ass to be able to receive and save them correctly in the database).