It was done on the request of the General Prosecutor, along with five other nationalist sites. They claim to have found evidence of them “justifying” Right Sector, the Islamic State, Al-Nusra, and other terrorist groups, fighting in Syria. Formulaic reminder about how the Islamic State is banned on the territory of the Russian Federation, in case anyone forgot. The resources in question “propagandize the ideas of national and religious discord, which constitute a threat to social peace and incite extremism.”
Apart from the inherent absurdity of implying Russian nationalists have sympathies for Islamists – an absurdity that any honest person can recognize regardless of ideological orientation – the more telling characteristic is no particular offending material was identified. This means “correcting” a sentence or even removing an article or two doesn’t appear to be an option. SiP’s editors seem to have recognized this, and are mulling switching domain names and directing readers to guides on how to install VPN. (Though the Russian government is working on banning VPN too).