The Church of Scientology.
Adherents of scientology have to take a set of courses to achieve the enlightenment prescribed by the movement's founder, Lafayette ("L") Ron Hubbard, a former sci-fi author who claimed he was chosen by extra-terrestrials to teach the new religion on Earth. Hubbard died in 1986 (although some adepts deny this), but Scientology lives on thanks to celebrity disciples such as Tom Cruise and John Travolta.
Lawyers of the Church of Scientology threatened the The Wayback Machine (aka Archive.org, The Internet Archive) with legal action (via a "cease and desist letter") that resulted in the removal from access of entire domains of its archive. A previous action by Scientology on freedom of expression attempted to force the Google search engine to block webpages with allegedly copyrighted materials. Scientology wrote in its cease and desist letter: This particular web site owner has placed our clients' copyrighted works and federally registered trademarks on his web page without the authorization of our clients. According, his actions are in violation of United States copyright law and I request Google either remove or disable access to the web site, "www.xenu.net". According to the website chillingeffects.org (provided by a consortium of law schools) , the the homepage of xenu.net does not contain any copyright violations.
It is alleged that the sect expects its adherents to supply the names and addresses of friends and relatives in the event that they might prove useful.