The Under Pressure video that was made in the 80's was, I believe, taken from BBC stock news footage plus other odds & ends. Queen & Bowie were unavailable for Top of the Pops or some other BBC show so they made up the film themselves and Queen/Bowie liked it enough to allow it's use permanently with the song. At least that's what I heard. Maybe someone else knows better?
I never heard it being done for Top Of The Pops, but I do remember reading somewhere that the video was done as it was because they couldn't get Bowie and Queen together in one place to shoot a video together.
Brian said it was banned in a lot of places because of the heavy use of newsreel footage (presumably, mainly refering to the riot footage they used). I remember MTV playing it a lot back in 82-83, but if what Brian says is true, they must have been one of the few to show it.
BTW, I remember back in the early 90's, seeing a really weird version of the video on VH-1, where they replaced all the silent movie footage with video footage with lots of weird video effects on them. You couldn't actually really see what it was that you were seeing because of the effects.
"Compromise? That word is not in our vocabulary"-Roger Taylor, quoting Freddie Mercury