No freedom of speech in the UK

Don't care about the UK's royal wedding? Don't like the UK's absurd inbred monarchy? Don't say so today in the UK, or you'll get arrested:

Three anti-capitalist activists who were planning a mock execution of Prince Andrew with a guillotine to mark the royal wedding have been arrested and detained at Lewisham police station.

[...]

A spokesman for the Metropolitan Police said: "This evening, 28 April, officers arrested three people – two males aged 68 and 45, and a 60-year-old woman – in Wickham Road, SE4 on suspicion of conspiracy to cause public nuisance and breach of the peace.

Rude? Yes. Tasteless? Yes. Caring too much? Absolutely. And yet they should have been allowed to mark the event in the manner of their choosing. Their display posed no danger to anyone, and no threat to "security". The only damage it would inflict was on the sensibilities of monarchists.

Meanwhile, thousands of street parties to celebrate the event get to go ahead without police intervention. The double-standard is evident. If you're a good little peasant, you can say so. If you're not, you don't. It is a clear content-based restriction on freedom of expression, and absolutely incompatible with the UK's status as a modern, liberal democracy. But then, so is the monarchy itself...