Editor's Note: Kara Alaimo, an assistant professor of public relations at Hofstra University, is the author of "Pitch, Tweet, or Engage on the Street: How to Practice Global Public Relations and Strategic Communication." She was spokeswoman for international affairs in the Treasury Department during the Obama administration. Follow her on Twitter @karaalaimo. The opinions expressed in this commentary are solely those of the author; view more opinion at CNN.
(CNN) - The red carpet for the premiere of "Cold Pursuit" was canceled this week after the film's lead actor, Liam Neeson, revealed during a press junket that he once considered carrying out a racist revenge attack because someone close to him said she had been raped by a black person.
The admission ignited a social media firestorm. Neeson was swiftly denounced by Twitter users as "disgusting" and an example of "white, toxic masculinity."
While Neeson later appeared on "Good Morning America" to clarify his comments and deny that he was a racist, the damage was already done. Neeson will now be known as an actor who contemplated a hate crime.
Many people mistakenly believe that there's no such thing as negative publicity. They couldn't be more wrong. Actors and other celebrities often speak out in public -- as Neeson was trying to do -- to promote their latest projects, and at times they venture into subjects that they're not particularly well suited to tackle. But, like everyone else, their bad behavior has severe consequences.
Of course, Neeson is not alone in his astonishing lack of public relations judgment. Here are a few other particularly memorable celebrity PR fails.
Roseanne Barr's racist tweets
These days, the increasingly ubiquitous use of Twitter by celebrities and other public figures has created plenty of opportunities for celebrities to get themselves in hot water -- not just for abnormal behavior, but also for inappropriate statements. The comedian Roseanne Barr learned this last year when ABC canceled her television show "Roseanne" just hours after she posted a tweet comparing former President Obama's senior adviser Valerie Jarrett to an ape.
Barr tried to respond with a time-honored failing PR strategy: Denying responsibility for her own behavior. Barr claimed the Ambien she had taken was to blame, causing the drug maker to memorably follow up with a tweet indicating that "while all pharmaceutical treatments have side effects, racism is not a known side effect of any Sanofi medication."
Coming on the heels of the #MeToo movement, Barr's firing was a powerful reminder that the media and entertainment industry has finally realized it cannot afford to be associated with celebrities who are responsible for egregious behavior like racism or sexual abuse -- no matter how big a following they command.
Tom Cruise's "Couch Jump"
In 2005, Tom Cruise appeared on The Oprah Winfrey Show to promote his newest film, "War of the Worlds." He deviated from the expected script, however, by professing his love for the actress Katie Holmes and, in a fit of excitement, jumping on Oprah's couch. The event resulted in what has been described as "one of the first celebrity memes."
Clips of the jump quickly spread across the internet. As the "Today" show noted 10 years later, the episode got so much attention that many people mistakenly remember him jumping more than once. It was an early lesson in how, in the age of digital technology, celebrities and other public figures must be especially careful about what they do in public, since memes are often shared and posted facetiously to illustrate points in other situations that are perceived to be similar.
But as Cruise began exhibiting more bizarre and inappropriate behavior -- such as publicly disagreeing with Brooke Shields about her postpartum depression and denouncing psychiatric medicine as part of his Scientologist beliefs -- the jump also came to be seen as a symbol of his perceived mental instability.
In 2010, Cruise explained the jump by saying, "I wanted the audience to be happy, just like I wanted to make my sisters and my mother happy when I did those skits as a kid. But I'll take responsibility for my actions."
Charlie Sheen's webcast rants
Since Cruise's infamous couch jump, such ill-advised public displays have increasingly become generated by celebrities through self-created content. Some of the most dramatic examples of this are Charlie Sheen's 2011 webcasts, in which he went on tirades against his former bosses on "Two and a Half Men," repeating phrases, smoking cigarettes through his nose and looking deeply disturbed.
Of course, publicly attacking former bosses is generally not ever a good public relations strategy for a celebrity or anyone else, because it ensures that anyone thinks twice before working with the person in the future. But documenting incidents of anger and apparently unstable behavior on the internet -- rather than seeking to address one's issues privately and in healthier ways -- also guarantees that a person will forever be publicly defined by such episodes.
The fact that the careers of these celebrities have taken serious hits since their PR disasters proves that no one is immune from the consequences of their actions -- no matter how rich or famous. But rather than realizing this from others, Neeson now stands poised to learn this lesson the hard way.