Twitter still keeps quite a few CEOs awake at night.

As a result, many of them continue to avoid the social networking site.

Today The Wall Street Journal reported on the Twitter-shy CEOs.

“Chief executives are under pressure these days to appear accessible and ‘authentic,’ but social media … poses risks for top managers and the companies they represent, in the form of lawsuits, leaked trade secrets or angered customers,” WSJ’s Leslie Kwoh and Melissa Korn wrote.

For all its worth—and the social network has a ton of worth—Twitter has its pitfalls, such as tweets that could lead to PR flare-ups, social media firestorms, and firings.

Here are 10 such tweets, with real-life examples:

The “Insult Your Client” tweet

“True confession but I’m in one of those towns where I scratch my head and say ‘I would die if I had to live here.’”

This tweet might seem innocuous—until you read the back story.

A PR professional at Ketchum fired off this message after landing in Memphis in early 2009 to meet with the firm’s client, FedEx. The company is based in Memphis, and many of its employees—including the executives—are natives of the area.

Employees spotted the tweeted, and they weren’t happy; Ketchum had to apologize.

This tweet became an early example of a major Twitter gaffe. Today, the person behind that tweet owns his own PR agency.

The “Insult Your Future Employer” tweet

“Cisco just offered me a job! Now I have to weigh the utility of a fatty paycheck against the daily commute to San Jose and hating the work.”

The story of “Cisco Fatty” has become Internet lore. Here’s what we know for sure: After Cisco offered Connor Riley a job, the young would-be employee sent her infamous “Cisco just offered me a job …” tweet (above).

Legend has it that Cisco spotted the tweet and rescinded the job offer. However, Riley has claimed she turned down the job before sending the tweet.

Either way, she didn’t land the gig with Cisco, and an Internet star was born: Cisco Fatty.

The “Oh Sh*t I Tweeted From The Wrong Account” tweet

“I find it ironic that Detroit is known as the #motorcity and yet no one here knows how to f**king drive.”

Tweeting from the wrong account is the leading cause of Twitter gaffes. A social media manager of PR professional thinks he’s updating his personal Twitter account when, in fact, it’s the account for his employer or client.

Take the above example, in which an employee of Chrysler’s social media agency, New Media Strategies, tweeted about Detroit’s traffic—from Chrysler’s account. He had meant it for his personal feed. Chrysler fired the agency, and the agency fired the guy who sent the tweet.

Here are two more examples:

• A Secret Service staffer tweeted from the agency’s handle: “Had to monitor Fox for a story. Can’t. Deal. With. The. Blathering.” Fox News had a field day; the Secret Service apologized and made clear it did not hold those views.

• A Red Cross employee sent this tweet from the nonprofit organization’s account: “Ryan found two more 4 bottle packs of Dogfish Head’s Midas Touch beer…when we drink we do it right.” This instance has a happy ending. The Red Cross teamed with the beer maker Dogfish Head to raise funds.

Moral of this story: Double-check from which account you’re tweeting.

Offending with tasteless jokes

“Japan called me. They said 'maybe those jokes are a hit in the U.S., but over here, they're all sinking.'”

This one is nearly as popular as the mixing up of Twitter handles, although it seems to mostly befall celebrities and athletes. Take the example above: In the days following the devastating earthquake and tsunami that struck Japan last year, comedian Gilbert Gottfried, then voice of the Aflac insurance duck, tweeted two insensitive jokes about the nation. Gottfried was fired.

There are more examples, unfortunately:

• Australian gold medal swimmer Stephanie Rice offered a homophobic rant on her Twitter feed in 20100. She called a tearful press conference to apologize, but she lost some of her lucrative sponsorships.

• Days before the 2012 Summer Olympics began, Greek triple jumper Voula Papachristou fired off a tweet that insulting an entire continent: “With so many Africans in Greece … At least the West Nile mosquitoes will eat home made food!!” She apologized, but not before getting kicked off the Greek Olympic team.

There is also at least one example of a brand issuing offensive tweets:

• The Durex South African brand tweeted a series of jokes that were highly offensive to women. (We won’t publish them, but you can find the jokes at Memeburn.com.) After first defending the jokes, Durex did the only sensitive thing: It threw its PR firm under the bus.

The “Encourage Violence Among The Citizenry” tweet

“Use live ammunition RT @MotherJones Sources in Madison say riot police have been ordered to clear protesters from capitol at 2 am #wiunion”

In 2011, Indiana Deputy Attorney General Jeff Cox suggested that police in Madison, Wis., use live ammo to clear protesters from the capital. Not good. Cox was fired.

The “9/11 Conspiracy Theory” tweet

“I just have a hard time believing a plane could take a skyscraper down demolition style.”

Athletes have a tendency to commit social media gaffes. Take Pittsburgh Steeler’s running back Rashard Mendenhall. In the aftermath of Osama bin Laden’s death, Mendenhall tweeted in defense of the slain terrorist, suggesting we (as Americans) only know half the story. He followed it up with a doozy about Sept. 11, 2001 (seen above). The tweets were removed.

Mendenhall still has his job (although he’s on the team’s disabled list for a torn ACL).

The “Celebrity Death Co-opt” tweet

“Remember Amy Winehouse by downloading the ground-breaking ‘Back to Black’ over at Zune … ”

In general, brands and individuals should take caution when it comes to celebrity deaths reported on Twitter. Often, they’re hoaxes. Although that wasn’t the case with pop singer Amy Winehouse, whose death last summer sparked an outpouring of grief on social media.

During that time, the tweet (above) from Microsoft U.K. encouraged its followers to buy a Winehouse album to honor her memory; the tweet directed people to Zune, Microsoft’s online marketplace for music and entertainment

Following a brief outcry, Microsoft apologized for the tweet.

The “Ransom” tweet

How you can #SupportJapan - http://binged.it/fEh7iT. For every retweet, @bing will give $1 to Japan quake victims, up to $100K.

Microsoft’s Bing account issued this tweet in the aftermath of the disaster in Japan last year. The Internet raged over the tweet, which resulted in an apology from Bing:

We apologize the tweet was negatively perceived. Intent was to provide an easy way for people to help Japan. We have donated $100K.

However, as a Seattle Weekly blog pointed out, Bing is certainly not the first company or celebrity to promote itself during a crisis. Stephen Colbert did so during the BP oil spill in the Gulf of Mexico.

The “Hashtag Hijack” tweet

“Millions are in uproar in #Cairo. Rumor is they heard our new spring collection is now available online.”

Here’s a similar gaffe that brands continue to commit. A tragedy occurs, and some social media manager decides to jump into the conversation with a promotion.

Kenneth Cole was the first to do it. As the Arab Spring erupted in Egypt last year, the designer’s account fired off the above tweet. Twitter users raged, and the company removed the tweet and apologized.

In another example, a retail company tried to tap into the barrage of tweets about last summer’s movie theater shooting in Aurora, Colo. CelebBoutique.com said: “#Aurora is trending, clearly about our Kim K inspired #Aurora dress ;)”

The backlash was swift and furious, prompting an apology from the online retailer and the explanation that its employees hadn’t checked the headlines before sending the tweet.

The “Criticize Your Co-workers” tweet

How many times have you wanted to tweet something disparaging about a colleague? You wouldn’t name names, of course, but just offer a veiled dig.

Maybe some of you are already doing this. If so, be careful.

According to a 2009 ABC News report, a copy editor at a Seattle-area newspaper would tweet his colleagues’ language gaffes.

“I went on a rant a month or so ago about our homonym-challenged reporters, some of whom—despite having more than 20 years of daily newspapering—clearly didn't know the difference between 'peak,' 'peek' and 'pique,' as well as between 'flair' and 'flare,'” he told ABC News.

Eventually, an employee at the paper spotted the tweets and copied them in an email that was sent around the newsroom.

The copy editor’s boss took him to the woodshed over the tweets.

[RELATED: I was fired for a tweet]

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