I'm preeeeetty sure

That in the UK as they are privately owned lpaces it's up to the owners and just like anywhere in the UK you can ask someone to leave. Yuo don't have to have them in your airport if you don't want them there. During the recent snow chaos there were reports of some people being told not to film on threat of being kicked out into the cold rather than the nice warm floors of the airport but the mgt then backtracked and said it wasn't a problem. I think it's just in certain areas though.