What is this TV license?

In the UK we have to have a licence to receive TV programmes. The money is used to fund the BBC and there are stiff penalties for not paying. We also have a lot of commercial TV here and there is pressure on the Government to abolish the licence. However, if that happened the BBC would become entirely commercial too. They have a remit to broadcast public interest information above and beyond ordinary entertainment etc and would obviously ditch the public interest stuff if they had to compete against commercial stations. They assume that everybody has a TV and if you don't buy a licence they come knocking on your door to find out why not! They have detector vehicles that can tell if you are receiving signals and cable companies have to declare who their customers are. When you buy a new TV set here your namec and address is sent to the licensing authority so they can check your name against their licence database. Yes, the fee is paid on top of any cable or satellite subscriptions. When I was a boy you paid licence fees for your radio too! And your dog if you had one!