In the West, throwing a custard pie at a politician is all part of the fun of politics. In Russia, it’s not so funny.

Earlier this week, unidentified people of Caucasian appearance, walked into a Moscow restaurant and threw a custard pie at Mikhail Kasyanov, leader of the opposition party Parnas. The attackers shouted “American agent,” and then walked out, undisturbed.

This appears to have been a planned attack because a video was soon posted on the pro-Kremlin LifeNews website.

Later that same day, near to the restaurant, the police arrested a number of Chechens, who turned out to be members of the Chechen Interior Ministry. Which perhaps explains why they were soon released.

The government media machine swung into action. The police said that they did not believe the attack on Kasyanov was a criminal matter, rather that it only qualifies as an administrative offence.

Dmitry Peskov, spokesman for the president, as so often, saw absolutely nothing of interest here. “There is no need for anyone to link this either to the Chechen leadership or any other regions of Russia. This is hooliganism, which, of course, is to be condemned.”

Kasyanov takes a somewhat different view of the affair. “I associate the attack with my political activities. I think that today’s attack is directly related to the fact that Kadyrov publicly threatened me, and I gave a statement to the FSB.”

The Chechen leader himself, in his characteristic manner, posted an ironic response on Instagram “Again, me)))) ?!” with pictures of Nikolai Baskov, the singer, his face smeared with cream, during a banquet in Chechnya.

But the situation is anything but funny.

Of course, throwing cakes and other food at politicians in the West is a part of the European culture of protest. Yet the attack on Kasyanov is different because it took place not in public, in full view of the cameras, but in a private space. In Berlin, say, throwing a custard pie is an expression of democracy – getting caught and fined is nothing to be feared, it is a badge to be worn with the pride of protest. In Russia, the custard pie is part of a campaign of intimidation, where the unidentified perpetrators act with a sense of impunity, egged on by the yellow press.

Dmitry Gudkov, the opposition Duma deputy, specifically linked the attack on Kasyanov to the attacks on the late Boris Nemtsov, who once had a toilet seat thrown at him; and for his opposition politics was murdered in cold blood almost exactly a year ago. For Gudkov, this attack on Kasyanov is a “quite deliberate dehumanisation of opposition politics … and when society no longer sees the man behind the cake, then it is already possible to kill.”

Leonid Volkov, one of the leaders of the Party of Progress, sees it the same way. “The attack on Kasyanov, just as with trolling, is a way of saying ‘we’re following you.’ And that is serious.”

Let us be clear, then, what that custard pie means. It says that in Vladimir Putin’s Russia, you could die of laughter.