If it's anything similar to Occupy Wall Street, wearing a suit would be taken to mean that a person is some sort of terrible exploiter of the proletariat.
Yes. My colleagues in London were advised to dress down during the protests to avoid drawing attention to themselves, I think this was fairly common at the time.
To be fair, if you had been found out, I think you would have deserved what you get for being such a glaring hypocrite. I am sure some people were giving up work to protest against a system. You were supporting that system, while using the protests as a place to stay.
What do you imagine this would have been? What would a "fair" reaction of the protestors have been?
The poster wasn't 'using' the protests, they were using a public park. It is hypocrisy of this movement to take over a public space and claim it for their own exclusive use, while not acknowledging that the fact that the police let them get away with this is a sign of their own privilege.
I think you have your wires crossed, I am just someone confirming the whole "you should dress down" advice - neither my london-based colleagues nor me (I don't even live in the UK) were living with the protesters during the occupy movement.
I remember visiting a similar protest, in my work clothes, to show support years ago. Being well dressed is taken as a sign you have some kind of malicious intention.
http://en.wikipedia.org/wiki/Occupy_London