Re: iPlayer Radio
I don't think this is the major reason. About all they can actually do is check that you haven't registered with an email address that you have used to tell them you don't need a license. The license payments (capita I think) and the iplayer accounts aren't linked up. As licenses apply to premises rather than people it's a bit tricky to do anyway (and has weird corner cases, and radio doesn't require a license, and and and...)
What it's actually about is worse. The BBC have long been pushing myBBC http://www.bbc.co.uk/blogs/aboutthebbc/entries/77bdafd0-20b3-414d-aa53-48786b194543 they want to know exactly what you're watching and reading on the BBC to build up customer profiles, it's an enormous personal data grab. It didn't take off on its own, but making accounts mandatory for access to (the highly successful) iplayer may have done the trick. There's no oversight of this strategy outside the BBC.
Biting the hand that feeds IT
