Actually, providers that use deep packet inspection block only specified URLs. If they don't have such equipment, they block IPs instead.
P.S. With that said, the links Type-kun posted works if I replace http:// with https://.
Updated
Posted under General
Kikimaru said:
A better line would be "all depicted characters are purely fictional and not based on any real-world adults or children".
Wouldn't really matter in Russia. They finally clarified what they block (seriously, 18 Nov 2013 - the very date they blocked danbooru). Any kind of information that "incites sexual feelings towards minors or justifies sexual relationships with minors", including audio, video, photos and text, is explicitly prohibited, with the exception of "works of art, where such content is justified by their plot or genre".