@NearJohnLewis
Firstly thank you for being the only poster to answer this question and explaining your reasoning and logic of protesting in the UK as a UK citizen asking for something from a UK Government, which makes perfect sense.
Whilst of course neither of us know the true motives of those attending the marches, I still find it deeply unsettling that out of the hundreds of thousands that attend there are none condemning Hamas. Yes Hamas are highly unlikely to listen to the concerns or criticism by marchers in London however there are plenty of protesters willing to openly condemn the Israeli Government who are equally highly unlikely to listen to the concerns or criticism by marchers.
It is strange that despite on every thread posters are anonymously willing to condemn or claim to condemn the actions of Hamas yet in real life at protests out of the hundreds of thousands of protesters there are literally none willing to do this in person.
I can only conclude that this is because they would like to but are too scared to do so for fear of being attacked (as happened to the Iranian man) or that in reality a large number are indeed sympathetic and supportive of Hamas. Or a combination of both.
Either way it doesn't reflect well on the "peaceful " marches that there is an element of intimidation (say the right thing or get beaten up) and or that a large number are terrorist sympathisers/ supporters.