Should we pay to use the iPlayer?

One of the things included in the government’s latest incursion into public service broadcasting is the idea of including the iPlayer in the BBC’s licence fee. Apparently an increasing amount of people- reckoned to be more than a half a million- are watching BBC programmes on the iPlayer without having paid the licence fee creating a potential loss of revenue for the Corporation. I’m not sure how they know this. Can the BBC actually know if someone watching the iPlayer on a phone for example belongs to a household that have not paid the fee? Aren’t they encouraging this anyway by increasing the amount of original programmes on the iPlayer? They’ve spent years trying to get more people to use it! Could they not forsee this when they first launched the thing?