A judge sentenced her to a year of rehab at a California facility run by Dr. Drew Pinsky and Sierra got another shot at reality television, appearing in the first season of Pinsky's VH-1 show "Celebrity Rehab."
One of 12 finalists during the show's second season, Clark told ABC's "Primetime Live" that as a 22-year-old he had an off-camera relationship with Abdul, then 40, that was at first platonic but later sexual.
Clark was abruptly booted from the show in April 2003 when producers learned he had been arrested for a domestic dispute with his sister the previous year.
After Clark's allegations, Abdul's rep issued a statement at the time saying she "will not dignify the false statements made by Corey Clark with a response. He is communicating lies about Paula Abdul in order to generate interest in a book deal."
The "Idol" producers at the time said they were never contacted by Clark concerning his claims.
Clark became an "Idol" footnote and Abdul continues to be a judge.
Last season it became clear that some "Idol" wannabes were not as green as they appeared to be. When it was discovered that Hennessy, the Irish singer with the big voice, had once been signed to a million-dollar record deal, some fans cried foul.
Hennessy only sold a few hundred CDs and was not under contract at the time she auditioned for "American Idol," which its rules state. Nonetheless, when New York magazine broke the story about Hennessy's and another contestant's previous record deals, a miniscandal ensued.
"The conceit of 'Idol' is that they are finding undiscovered talent," Hibberd said. "The show shouldn't violate that. The fact that some of these contestants got some attention but haven't broken through in a major way, I think the producers were right not to arbitrarily exclude those people."
The other controversy that broke last season involved some scantily clad photos of Hernandez when he worked as a stripper at a mostly male Phoenix nightclub.
The show's producers were unfazed. Warwick told TV Guide's Web site: "We've had strippers on the show before. We're never judgmental about people who do things like that. If it were some sort of heavy porn, then maybe we'd have to take action. But certainly not on this."
"Idol" did dismiss contestant Frenchie Davis during Season 2 in 2003, after it was discovered that she had once appeared on an adult Web site.
The show left it to the fans to decide and they did pretty quickly -- Hernandez was the first of the 12 finalists to be eliminated.
The year before, another set of racy photos made headlines. After topless photos of New York semifinalist Barba were leaked on the Internet, "Idol" took the unprecedented step of allowing her to stay.
Barba explained at the time that these "were photos of my personal life that got exploited without my consent."
Cowell defended her, telling USA Today, "These people haven't done anything illegal; that's their private life."
Hibberd said "Idol" fans shouldn't be surprised if more of these types of scandals turn up. "It goes with some of the exhibition qualities that drive people to audition for the show," he said.