I'd be tempted to string them along. If you pay your taxes, these people are basically stealing from you by increasing fraud and decreasing the willingness of

I'd be tempted to string them along. If you pay your taxes, these people are basically stealing from you by increasing fraud and decreasing the willingness of others to pay taxes, as well as stealing from other people. I'd be fine with IRS CID spending $100 to catch $1 of criminal predation on taxpayers, here.