Chris

I suspect TVL have found, from their vast experience of running this operation, that most people who simply ignore them, are trying to avoid paying for a licence that they should have, and that most people who don't need a licence are happy to confirm this with them.

That's a generalisation, of course. There are bound to be people who object on principle to being treated as a potential criminal and therefore ignore all communications from TVL, and are uncooperative should one of their staff pay a visit. However TVL would not take this approach if they believed they were mostly pursuing people who didn't owe them anything. Their operation costs money to run. That expenditure can't be justified if it doesn't result in licence fees being paid.