...is largely irrelevant to the question (he has worked in war zones and those tend to be, ummm, less respectful, shall we say....) and is prone to change its mind at the drop of a hat. There's sectors in the British political scene who have no problem with promoting acts of terror and murder against those they don't like and it's kinda unlikely that they'll hold a referendum on whether to murder a street artist if he posts something they find offensive.
(Depending on which part of the political scene you find yourself allied with, you'll doubtless point to other sectors, but it seems very very unlikely that anyone would subscribe to the notion that there aren't influential psychopaths in Britain, even if there's no agreement on who those are.)
Britain DOES enshrine a right to privacy, as Rupert Murdoch keeps discovering, and much of Europe mostly enshrines the same ideas (occasionally even more strongly). As for "public interest", I would LOVE to hear an explanation of precisely what public interest this serves. No, the public being interested is not the same thing.