A Suppressive person in Scientology is anyone who campaigns against Scientology or anyone who has been declared suppressive by those higher in the organisation. Scientologists believe that any action taken against Suppressives is fair game and morally acceptable. People declared suppressive can find that their lives are ruined.
In the official Scientology definition a suppressive person is somebody with an antisocial personality, which according to L. Ron Hubbard is about 2.5% of the population. In actuality, the Church of Scientology uses the label mainly on critics and perceived enemies and rivals of Scientology.