However, the Boluan Fanzheng period also saw many controversies, such as disagreement over views on Mao, the inclusion of the "Four Cardinal Principles" in China's Constitution which upheld the CCP's one-party rule in China, and legal controversies including the fact that many of the leaders and perpetrators in Cultural Revolution massacres received little or no punishment at all.[1][16][17][18] The CCP has not fully declassified the documents related to the Cultural Revolution and has been restricting academic studies and public discussions of it within the Chinese society.[19][6][7][8][9][10] Additionally, there have been concerns about the reversion of the Boluan Fanzheng reforms and return to one-man rule seen under Mao since Xi Jinping became CCP general secretary in 2012.[11][26][27][28][29]