Audit of Fee Waiver Abuse

Hi there...does anyone out there perform periodic reviews over potential abuse of fee waivers? For exmaple, how would you go about identifying someone at the branch waiving fees (e.g. NSF, overdraft..) excessively for friends and/or family? Are there any indicators and/or red flags that an auditor should be cognizant of besides the number of occurrences?

Thanks!