On the other hand, L. Ron Hubbard has proclaimed that all critics of Scientology are criminals. Hubbard wrote on numerous occasions that all of Scientology's opponents are seeking to hide their own criminal histories, and the proper course of action to stop these attacks is to "expose" the hidden crimes of the attackers. The Church of Scientology does not deny that it vigorously seeks to "expose" its critics and enemies; it maintains that all of its critics have criminal histories, and they encourage hatred and "bigotry" against Scientology. Hubbard's belief that all critics of Scientology are criminals was summarized in a policy letter written in 1967: