CHICAGO—So, you fail to take a deep breath and to count to 10—and you post something you probably shouldn’t on Twitter or Facebook, or somewhere else online.

Hopefully, it blows over without doing too much damage. But what if you’re famous and have thousands, if not millions of virtual followers?

NFL star Larry Johnson was released by the Kansas City Chiefs after questioning his coach and posting gay slurs for all the world to see. California Gov. Arnold Schwarzenegger was criticized for pulling out a big knife in a video that was posted as a “thank you” to constituents for suggesting ways to cut the state budget.

Those are but two of the recent controversies that social networking helped ignite—and far from the last in an era when fans and gawkers are just waiting for sports stars, celebrities and politicians to say something embarrassing or naughty. New technology makes it that much easier for stars to do that.

Syracuse University star receiver Mike Williams discovered some pitfalls when he was suspended from the football team this fall, and then quit shortly after saying he hated college on his Facebook page.

“I can’t see me doing this for long ... hint, hint,” Williams also wrote, according to the Syracuse student newspaper.

Those kinds of posts are causing more universities, pro teams and even some movie studios to try to clamp down on the off-the-cuff content their stars put online. Or, at the very least, celebs of all kinds are being encouraged to think before they post.

Sometimes, it’s about protecting reputations. In other cases, it’s about keeping sensitive information from leaking.

One could argue that some celebrities, athletes and politicians have done a pretty good job of making fools of themselves for a long time without social networking.

However, while there are obvious dangers, all of this “microblogging,” as it’s known, can be worth the risk: Fans like having this kind of direct access to public figures and can be quite loyal to those who are good at it.

And even if there’s an online stumble, here or there, well, that can just make celebs seem more real.

“It’s a way to understand that they are human,” says April Francis, a 26-year-old Chicagoan who works as an “identity consultant,” which includes help with wardrobe, branding and public relations for her clients.

On Twitter, she follows everyone from burlesque performer Dita Von Teese to basketball star Shaquille O’Neal—but recently dropped author Margaret Atwood because she thought Atwood was “mind-blowingingly boring.”

For a lot of fans, it is that—not controversy—that’s the kiss of death these days.

“It comes down to the interest factor,” says Allen Chen, a 30-year-old university worker from Yonkers, N.Y., who follows several professional athletes and authors on Twitter and thinks it’s best when they are “funny, entertaining and snarky.” He recently dropped a former New York Knick (Stephon Marbury) and a current one (Nate Robinson) because he says they were none of those things.

Sometimes it’s the celebrity who loses interest in social networking. Teen pop star Miley Cyrus recently stopped tweeting because she grew weary of tabloids using material she posted.

More often, though, Hollywood types are more than happy to share what some might consider too much information, evidenced on Wonderwall.com, a site that tracks some of the more questionable or buzz-worthy things celebrities tweet.

Consider this one from actress Demi Moore: “grabbing my hubby and putting on my birthday suit.....to snuggle.......goooood night. until tomorrow!”

It’s all part of the growing school of thought that controversy, or titillation, actually helps a celebrity’s career by getting them noticed, says Richard Laermer, a New York publicist.

“The new PR is about fame that starts and stops with everything that people hear about you. So in order to rise above the noise, you have to be outrageous and controversial,” says Laermer, who talks about the trend in his book “2011: Trendspotting.”

Of course, there are limits, he says, noting that most high-profile people generally don’t go “astray from who they want their fans to think they are.”

In some instances, a few celebrities and athletes have managed to use social networking to help resurrect their images. Chad Ochocinco, the brassy wide receiver for the Cincinnati Bengals, is one of them and even has his own iPhone application.

In the end, some also might argue that the damage players such as Larry Johnson and Mike Williams did to their reputations likely won’t be that long-lasting.

Johnson is now playing for the Bengals, a team known for taking on troubled players, though he’s a backup running back. And some suspect Williams, who was a junior at Syracuse, will surface in next year’s NFL draft.