Pickman's model
sunset spires and twilight woods
yeh if it's one person but not if it's a dozen or moreExcept that although unlawful, the plod will still have that all encompassing get out for stopping you doing anything because "terrorism", and I'd wager that in the moment they'd choose potential ticking off for over extending their powers and confiscating and 'accidentally' deleting footage from a camera than risk being caught doing something which would have them prosecuted.
https://netpol.org/2012/07/27/a-rough-guide-to-filming-the-police-during-a-stop-search/