Just found this:
"In sum, the OCC's interpretation that “customer” includes payees who present a check to a drawee bank for payment due is controlling.   Consequently, the national banks are authorized by federal regulation 12 C.F.R. § 7.4002(a) to charge non-account holding payees a check-cashing fee. "http://caselaw.findlaw.com/us-5th-circuit/1361617.html
Take note: this is a fifth circuit decision, and Illinois is in the 7th circuit. So, this case isn't legally binding on Illinois transactions. But, it is persuasive.