What tracking occurs when sending money through Western Union or MoneyGram?

Yes an ID is required for a Cash-Over-the-Counter (COC) transaction. You may be required for a supplementary ID as well. In either case, a copy of your ID is retained for internal KYC records. The information supplied is then checked by the mainstream WU/MG systems for AML checks and OFAC/Blacklist Checks. If you are flagged, they will let you know immediately (or in some case, in an hour or so).