I just returned a couple of weeks ago from Moscow and St. Petersburg. No issues with taking photos including the Metro, train stations, on the street, or markets. In fact everyone I met was gracious and accommodating. I observed many instances of Police checking papers (including my own) but they where clearly not interested in me taking photos just my credentials. There were the usual restrictions in museums and churches but I encountered nothing I wouldn't have expected anywhere else in the world. I admit that I did not try to shot pictures of nuclear reactors or secret military installations.
Bill