Perhaps some sort of TV license number check could be made when people use the iPlayer, without incurring additional costs? After all, I can use either a bank, a cash dispenser or an on-line facility to manage my money and it doesn't cost me any extra for having multiple facilities at my disposal.
The BBC ought to be doing likewise - or perhaps they're looking for ways to cover the lost income from BBC Worldwide now the regulators have spotted this lucrative cash cow.