And here is an except from South Park's trapped in the closet episode where they to explain the story of Xenu. You can see the full episode on south parks website here.
This episode stirred up a lot of trouble and South Park is currently still in legal battles with Scientology and finally here is the classified tape of the cults founder, L. Ron Hubbard talking about Xenu.
Scientologist actively deny the existence of Xenu believing that if someone reads the material before they are "ready" meaning before they pay an estimated amount of $365,000 for their bridge they will catch pneumonia and die.
There are several videos similar to this done both at protest, on radio shows, and news programs and even though the cult believes so strongly in not telling the truth about Xenu some Scientologist do like the Spokesman of New Zealands branch of the Church of Scientology.
OT: Operating thetan: The upper levels of Scientology that are closely guarded