If in fact cheques were being cashed in the fashion suggested, it would constitute money laundering which is illegal, and all financial institutions carefully monitor each and every transaction for money laundering. So if there was no justification for such transactions i.e., always cash, (there are many criteria) flags would be raised within the banking system and addressed immediately by the compliance manager(s) within the organization. Financial institutions have very specific and tight regulations for monitoring, controlling and reporting any suspicious transaction(s).