Bottom line, if Plod wants you moved on or stopped, he'll find some law which gives him the excuse.
As did many by using the Terrorism Act to prevent folk taking photos in public places, confiscation memory cards (or film) of getting shots deleted.
This sort of action leads to a invite to a no tea no biccies interview. as would trying to move the folk in the video, might get away with it for one or two, but that number would quickly lead to official action against any officer involved and 15 minutes of fame on Youtube