Mark Wilson writes: 13 years ago, BBC3 launched in the UK. Last night, the TV station broadcast over the airwaves for the last time. In a bid to slash expenditure, the youth-oriented channel that launched countless comedy careers is now only available online. The likes of Being Human, The Mighty Boosh, Gavin and Stacey, and the like will live on, but only on the web — which the BBC is spinning as an opportunity to be freed from the constraints of regular scheduling. The change has been known about for some time now, and there have been a number of campaigns and petitions to try to get the BBC to change its mind.