In response to the terrorist attacks of September 11, 2001, almost all of the twenty major industrialized and emerging economies (G20) passed anti-terrorism laws that, to protect their citizens, also restrict civil liberties and expand the powers of the executive branch in the name of national security to this day. The comparative focus of this study is on national laws and policies of the G20 states and shows that even today, 20 years later, the vast majority of anti-terrorism laws remain in force. Authoritarian states repeatedly use the "war on terror" as a justification to silence opponents of the regime and opposition figures in their countries. In democratic states, many of the originally temporary encroachments on privacy, such as telecommunications surveillance or the collection of biometric features, remain in place and have been normalized by being written into permanent law.