No, not just memes that encourage people to riot on the streets. But you know that, and it's funny that you think that you'd think that meme encouraging that should be enough to land someone in jail anyways. I mean, it fits very well with the servile "king's subject" mentality that your average Brit has but still, always funny to come across.

(And no I'm not american, but the UK is on the opposite end of rationalizing every single restriction and siding with authorities every single time. It's extremely pitiful to see)

Who got jailed for a meme that wasn't inciting to riot?

Peaceful protest that power doesn't like is a riot

Example? Or is this hypothetical?

I can think of Canada's Emergency powers act being invoked over the Freedom Convoy.