Pioneer movements have existed and still exist in countries where the Communist Party is in power as well as in some countries where the Communist Party is in opposition, if the party is large enough to support a children's organization. In countries ruled by Communist Parties, membership of the pioneer movement is officially optional. However, membership provides many benefits, so the vast majority of children typically join the movement (although at different ages). During the existence of the Soviet Union, thousands of Young Pioneer camps and Young Pioneer Palaces were built exclusively for Young Pioneers, which were free of charge, sponsored by the government and trade unions. There were many newspapers and magazines published for Young Pioneers in millions of copies.