Director Alex Gibney's explosive HBO documentary about Scientology, "Going Clear," which is based on Lawrence Wright's best-selling book of the same name, premiered Sunday night at the Sundance Film Festival.

After HBO had 160 lawyers preparing for the doc about the litigious church, the film quickly became the festival's premiere with the most buzz.

Premiere of #goingclear my film on Scientology at @sundancefest in 90 minutes. Very excited. Many peeps from film here. — Alex Gibney (@alexgibneyfilm) January 25, 2015

Dozens of people still wandering around, looking for seats at the Marc for GOING CLEAR. None to be had; they let too many in. #Sundance. — Josh Lincoln Dickey (@NotoriousJLD) January 25, 2015

Crowd control at Going Clear, Gibney's Scientology documentary, is out if control. Where's Overlord Xenu when you need him? — Ty Burr (@tyburr) January 25, 2015

After festivalgoers and the press viewed the film for the first time, a few notable tidbits about Scientology came to light.

1. The Church of Scientology allegedly split up Tom Cruise and Nicole Kidman.

The Daily Beast's Marlow Stern, who was in attendance, explains:

According to the testimony of Marty Rathbun, formerly the second-highest ranking official in the Church of Scientology who left in 2004, Scientology head David Miscavige was suspicious of Cruise’s second wife [Nicole Kidman], whose father was a renowned psychologist in his native Australia. Scientology is vehemently opposed to psychiatry and psychology, and Rathbun claims that because of Kidman’s father, she was labeled a "Potential Trouble Source" (PTS)...

"I was to facilitate the breakup with Nicole Kidman," Rathbun says in the film.

Rathbun alleges in the film that the Church of Scientology then waged an aggressive campaign to get Cruise to dump Kidman, including having a private investigator wiretap her phone ... Furthermore, Rathbun says the Church of Scientology "re-educated" Cruise's adopted children with Kidman, Connor and Isabella, into turning against their mother so that Cruise could retain custody.

Read the Daily Beast's full review here.

Jim Smeal/WireImage via Getty Images 2. John Travolta allegedly stays with the church because it has too much dirt on him and has threatened to make his private info public.

Vulture's Bilge Ebiri writes:

Travolta, it's suggested, is kept in the group because they have mountains and mountains of dirt on him, the result of years of spiritual "auditing" (the process by which Scientologists basically reveal their deepest secrets, which are then cataloged and brought out whenever someone needs some, uh, encouragement, as the Mafia likes to say).

Read Vulture's full review George Pimentel/Getty Images 3. The church allegedly mistreats its members, in some cases physically abusing them, and threatens and harasses those who leave the faith.

The Hollywood Reporter writes that in the doc "well-known former members paint detailed portraits of how abusive and controlling the organization could and still can be."

4. Church of Scientology membership has apparently dwindled to 50,000 worldwide.

Mashable's Josh Dickey, who saw the film, writes, "It's hard to believe Scientology still retains some 50,000 members in the social age (down from a peak of about 100,000 in the early '90s)."

5. "Going Clear" estimates Scientology has amassed over $1 billion in tax-free wealth.

"An organization that's managed to retain its tax-exempt status based on its classification as a religion according to the IRS with access to some $3 billion in assets, is still a fearsome beast to contend with," writes The Hollywood Reporter in its review.

"The documentary is a broadside against the controversial religion," Variety adds. "It argues that Scientology exploits its tax exempt status to amass millions of dollars in property and donations, behaving more like a business than a charity."

6. A few more interesting celebrity nuggets from Los Angeles Times writer Amy Kaufman, who was at the screening:

Doc sez Scientology bought actress Nazanin Boniadi $20K of clothing from Burberry etc& removed braces/dyed hair so she cld be poss Cruise gf — Amy Kaufman (@AmyKinLA) January 25, 2015

No mention of Katie Holmes in @alexgibney's Scientology doc. I was going to ask why, given it talks about Kidman, but wasn't called on. — Amy Kaufman (@AmyKinLA) January 26, 2015

Travolta apparently knew his friend Spanky was kept in prison camp at Scientology HQ, scrubbing toilets & w/o her kid. But didn't intervene — Amy Kaufman (@AmyKinLA) January 26, 2015

The film received a standing ovation after its Sundance premiere.

Congrats @alexgibneyfilm: - brilliant docu #goingclear Will have huge ramifications for Scientology. About time. @sundancefest — laura michalchyshyn (@lmichalch) January 26, 2015

Great job @alexgibneyfilm on GOING CLEAR: SCIENTOLOGY AND THE PRISON OF BELIEF. Informative and disturbing look at http://t.co/12ihaIajgh — Jason Hirschhorn (@JasonHirschhorn) January 26, 2015

"Going Clear" will air on HBO beginning March 16.

The Church of Scientology published a full-page ad in The New York Times earlier this month accusing the film of reporting false claims about the controversial religion.

The Scientology ad calls out "Going Clear" director Alex Gibney for supposedly not allowing the organization to respond to claims made in the film.

Specifically, the ad asks whether the documentary is "a Rolling Stone/UVA Redux" — a reference to a now notorious article in the magazine about rape at the University of Virginia.

Former Scientology members hope this film will have the power to force major shifts within the church.

"I hope this movie increases public pressure for the church to change its abusive practices," one former Scientology member told The Times.