It's funny... according to Scientology, their views on ex-members are eerily similar to Watchtowers:
The Suppressive Person seeks to upset, continuously undermine,
spread bad news about and denigrate betterment activities and groups.
Thus the Anti-Social Personality is also against what Scientology is
about—helping people become more able and improving conditions in
society. As anyone can think of many examples of a Suppressive Person,
this concept is not limited to Scientology. However, when such a person
is connected to Scientology, for the good of the Church and the
individuals in it, such a person is officially labeled a Suppressive
Person so that others will know not to associate with them.
To be declared a Suppressive Person is extremely rare and results in
expulsion from the Scientology religion. This occurs in instances of
serious offenses against the Scientology faith and can also occur when
an individual is found to be actively working to suppress the well-being
of others. This can be done through criminal acts already recognized by
society as unlawful or through the commitment of acts deemed
Suppressive Acts in the Scientology Justice Codes—which includes the
Suppressive Act of publicly renouncing the faith, an act which in
Scientology, as well as almost every religion, is grounds for
automatic expulsion.
When someone has been expelled from the religion, that person loses
both his or her fellowship with the Church as well as with other
Scientologists. The condition lasts until they have been restored to
good standing. Once the person has been restored to good standing, the
prohibition against fellowship with other Scientologists is lifted.
Similar practices have been part of religious communities for thousands
of years and have been recognized by courts of law as a
fundamental right.
http://www.scientology.org.uk/faq/scientology-attitudes-and-practices/what-is-a-suppressive-person.html