Yup, there's a thing called a "suspicious activity report": https://www.occ.treas.gov/topics/supervision-and-examination/bank-operations/financial-crime/suspic

Yup, there's a thing called a "suspicious activity report": https://www.occ.treas.gov/topics/supervision-and-examination/bank-operations/financial-crime/suspicious-activity-reports/index-suspicious-activity-reports.html https://www.occ.treas.gov/topics/supervision-and-examination... https://en.wikipedia.org/wiki/Suspicious_activity_report https://en.wikipedia.org/wiki/Suspicious_activity_report https://www.fincen.gov/reports/sar-stats https://www.fincen.gov/reports/sar-stats Millions of these are filed per year. Obviously not all of these - probably not even most of these - are about actual crimes or end up in actual prosecutions, but the banks still have to file them.