1. a check is a bank instrument, so yes checks are covered under this law.
2. the law is in effect right now, the 270 period is for the Treasury Dept to come up with enforcement guidelines for the law.
3. you're right the teller won't care about the check, it is when it is presented at the clearinghouse the check could be flagged (notice I said could)
the law basically wants banks to code all transactions similar to the way credit card transactions are coded now. This way the government can regulate commerce depending on how the transaction is coded. No one knows how this can be done. I would think they would start by 'coding' certain known bank accts as Internet Gambling. This would intale someone compiling a list of known Internet Gambling Companies Bank Account numbers.
Any checks, wires, transfers of any kind coming from the known bank account would be labeled as Internet Gambling and then in turn be blocked.
Since the number of Sportsbooks Bank Accounts would be less than the number of Players bank accounts, the Treasury Dept will probably recommend that nothing can be done or should be done to accounts on the recieving end.
heck banks may even have a service fee to charge players that could look like this on your bank statement: Denied Internet Gambling Transaction $50 each (just like a bad check fee)
I foresee a huge cat and mouse game where books have several dozen "uncoded" bank accounts that will be used until they are identified and then coded.