You didn't seem to think it was unclear when you wrote:
Remember when liberals were outraged when Russian protesters were arrested for showing blank pieces of paper?
The UK is now in the same stage of slide toward autocracy, evidently.
The only reason you had for saying that people in the UK were arrested for showing blank pieces of paper was a statement that said it was "unclear if anyone had been."
So just to make this very clear, you've turned "It is unclear that X" into "X evidently happened", and when I said that it didn't you've said that you said it was "unclear."
There have been plenty of reports of people being arrested for displaying the slogan “I oppose genocide, I support Palestine Action,” and no reports of people being arrested for holding blank pieces of paper, so it's actually quite clear what happened - the random internet guy got a bee in his bonnet about the factual description of people making sure they made it to the demonstration in order to be arrested en masse (rather than in a trickle) and decided to use weasel words to make it sound like people got arrested for something ridiculous, and you took the bait.