Thank you Lucid it would seem there has been a change in the law at one time you needed a license to have a TV even if you did not watch it but that has changed.
I am sure you are allowed to use built in aerials and the aerial rule is to stop you using the aerial fixed to the house.
However the TV license has traditionally been poor English as one time it defined the TV as the device for turning radio frequency signals into electrical signals which when I went to school was called an aerial? The TV amplifies and decodes TV signals and displays or stores them.
I have talked about a sky box which does not decode a TV signal until it is watched but most TV law is built on case law not the English of the license. I remember some one with a monochrome TV was given a video recorder and was taken to court because the video recorder records in colour. The Judge found the old lady guilty as he said other wise it would set a president but only fined her £5.
The point is all aerials receive colour it is down the the equipment to if colour information is displayed or stored.
The big word is of course "Broadcast" any signals transferred one to one are not broadcast I am not permitted to broadcast except to call CQ I have to make contact with an individual and then send my signals to them even if I know others are listening so if a see an accident on the motorway I can't tell anyone about it until I have made contact with an individual.
So if when you go to a web site and watch video content you have the ability to start it from the beginning when you want then it's not broadcast, but if when you start to view you see it are some pre-set point then it's broadcast so
http://www.tvcatchup.com/ in spite of the name is broadcast and you need a TV licence to watch it.
I have a licence so it does not worry me at home. However I have carried a Yagi and HB9CV beam aerial both up mountains and to car parks and erected them on a temporary basis and my equipment is capable of receiving broadcast transmissions and displaying results on my computer screen.
I have already had an argument with a TV detector van guy where I was trying to tell him I needed a radio licence not a TV licence to receive and transmit slow scan TV which if printed rather than viewed on a screen would be called fax. It would seem that what ever was in the TV that detector vans detect was still transmitting even though the item being viewed was being transmitted from my mate a mile down the road. We were using 70cm so close to TV frequency. This was late 1960's early 1970's era and as I said at that time it was owning a TV not using it and we had taken to set up to a house which was not licensed and signing as alternative. I am sure if we were using CB and not amateur radio we would have been charged.
The problem with case law is keeping up. What was legal yesterday may be illegal today or reverse. I have often wondered if listening to TV needs a licence? My FT50R will tune to TV band but has only a speaker no screen? Since my only battery failed I use a larger battery and a cable to connect it so not running off internal batteries. It does have a wide band receive as well as narrow band used for amateur stuff so when bored on a RAYNET event I have tuned into the news normally radio but could select TV and connected likely to a HB9CV aerial.