Blocking of Wikipedia in Russia is possible, — the participant of Wikipedia Stanislav Kozlovsky has warned

This will break many links.

Readers who are accustomed to drawing knowledge from Wikipedia or Wikiguide will suffer greatly. We, the readers here, will gradually lose access to other – not state-owned points of view.
There will be a noticeable blow to publications that use free photographs, drawings, videos from Wikimedia Commons. The trouble will hit publishers, photographers and archives who publish their content in this photo bank for free use.
Blocking Wikidata will hit semantic and search robots that receive logical connections between concepts from there.
Blocking Wikinews will close access to the most independent, freest media in our country.
Many will have to access these sites through VPN servers outside of Russia.
The generosity of individuals and the mercy of legal entities will receive a cruel lesson from the state department.