All checks cashed are traceable no matter where they are. They keep extensive records. If you're cashing a check it's finger prints, multiple ID, maybe a photo, and signitures. If it's WU at a checks cashed, WU has black listed people for small amounts of money.
Debit cards by books are run through Credit Unions. Not sure international law, but if they are based in America it would be anything over $10,000 reported which you probably already knew.