July 23, 2009 -- Why in the world is Calif. Gov. Arnold Schwarzenegger seen wielding a two-foot-long knife in a video link posted onTwitter?

In a 27-second clip posted Tuesday, the husky governor addresses the Twittersphere while holding a two-foot-long knife.

While the state wrestles with a $26 billion deficit, the celebrity turned Republican governor posted the video as a thank-you to constituents for their ideas on how to pay down the massive deficit, particularly one suggestion to autograph and then auction off state-owned cars.

"Hey guys, I just want to say thanks very much for all the great ideas you're giving me," he said. "You come up with great ideas. Why not just sign the cars since you're a celebrity governor? Sign the cars and sell it for more money. … That's exactly what we're going to do."

According to The Associated Press, Schwarzenegger's spokesman Aaron McLear said the knife was a gift from a friend and arrived Tuesday. He also said the governor actually does intend to sign state vehicles before they're auctioned off in late August. Officials estimate that selling 15 percent of the state's 40,000 government-owned cars could raise about $24 million.

When a reporter asked Schwarzenegger Wednesday whether the video was appropriate, given how seriously the budget cuts are affecting the lives of some Californians, the governor went on the defense.

"Not that I have fun with making the cuts -- they sadden me -- but ... that doesn't mean that you cannot wave a knife around, or to wave your sword around, to get the message across that certain cuts have to be made because it's budget time," Schwarzenegger said during a news conference.

Schwarzenegger's not the first public figure to court controversy on Twitter.

New Tool Brings New Mistakes

Most would argue that the micro-blogging site that has attracted millions of users, including celebrities and politicians, is a powerful tool for communication. But it's amazing how much trouble 140 characters can cause.

Just like hitting "reply all" instead of sticking with the simple "reply," one errant Twitter message -- the maximum post is 140 characters -- available for all with an Internet connection to see, can send its author ducking for cover.

"While Twitter is a new tool that brings with it some new possible ways to make mistakes, people make mistakes in all of the different communications we already have," said Sarah Milstein, author of "The Twitter Book" and social media consultant (she was the 21st user of Twitter). "What makes Twitter different is that the messages are public so that anyone can see them."

Like a blog, Twitter is public but, unlike a blog, the messages, photos and links can easily be re-tweeted or passed along virally to other users, she said. That combination means that regrettable postings can be sent far and wide and then, to make matters worse, easily searched for on Google.

"Be thoughtful about your posting, be interesting, because Twitter is a medium where people choose to get your message," Milstein said. "If you're thoughtful about your individual messages, it also helps to take a step back when you're doing something potentially inflammatory or that you may regret later."

Here are nine other people who might have been helped by that bit of advice.

Author Feuds With Critic on Twitter

In early July, author Alice Hoffman caught some flack for getting huffy with a critic via Twitter. Hoffman wasn't too pleased when Roberta Silman said Hoffman's novel "lacked the spark of earlier work" and that "the author doesn't deliver" in a Boston Globe review of her new book, "The Story Sisters."

According to the tweets reprinted on Gawker, she called Silman a "moron" and said "no wonder there is no book section in the Globe anymore."

Her tweets continued, until finally Hoffman committed a major social media no-no and posted Silman's phone number on Twitter in case followers wanted "to tell Roberta Silman off."

Her tiff generated such a buzz that she finally issued an apology through her publicist.

"I feel this whole situation has been completely blown out of proportion. Of course I was dismayed by Roberta Silman's review which gave away the plot of the novel, and in the heat of the moment I responded strongly and I wish I hadn't.

"I'm sorry if I offended anyone. Reviewers are entitled to their opinions and that's the name of the game in publishing. I hope my readers understand that I didn't mean to hurt anyone and I'm truly sorry if I did," she wrote.

Arizona Man Says Tweeting About Vacation Led to Robbery

If you're heading out of town, should you think twice before tweeting it out to your followers?

One Arizona man thinks so.

Before leaving with his wife in June, Israel Hyman told his approximately 2,000 Twitter followers that they were "preparing to head out of town," that they had "another 10 hours of driving ahead" and later, that they "made it to Kansas City," CNET reported at the time.

But when they returned home, they found that someone had broken into their home and stolen video equipment he used for his video business – to the tune of a few thousand dollars.

"My wife thinks it could be a random thing, but I just have my suspicions," he told The Associated Press. "They didn't take any of our normal consumer electronics.

"The customers have never met me in person," Hyman said. "Twitter is a way for them to get to know me. I forgot that there's an inherent danger in putting yourself out there."

Det. Steven Berry of the Mesa Police Department, which is investigating the burglary, said: "You've got to be careful about what you put out there. You never know who's reading it."

Al Roker Tweets From Jury Duty

In May, Today show weatherman Al Roker found himself in a blizzard of headlines when he snapped photos of potential jurors on his iPhone and -- in violation of court rules -- posted them to his Twitter page.

Newspapers had a ball, with the New York Post headlining a story with, "Oh, What a Twit!" But Roker promptly apologized to officials at Manhattan's Criminal Court. He called the mistake "inadvertent," but defended himself.

"Folks need to lighten up," he said in a later Twitter posting. "I'm not breaking laws . . . just trying to share the experience of jury duty. One that I think is important and everyone should take part in."

David Bookstaver, a spokesman for the state Office of Court Administration, echoed Roker's sentiment, while saying the picture taking was "ill advised."

"No harm was done," Bookstaver said, adding: "What's more important is this shows Al came to do his civic duty, and we're happy about that. It's a good example that nobody's exempt."

Mavericks Owner Slapped With $25k Fine for Tweeting

In March, the NBA came down hard on Mavericks Owner Mark Cuban for tweeting grievances against referees. The NBA hit him with a $25,000 find for publicly criticizing officials after the Denver Nuggets beat his team, the Dallas Mavericks.

Using Twitter, he complained that Denver's J.R. Smith was not called for taunting Antoine Wright after he missed a shot.

After he heard about the fine, he wrote, "can't say no one makes money from twitter now. the nba does."

Top House Republican Tweets from the Green Zone

We all want our elected officials to be transparent in their motivations. But maybe there's such a thing as too much transparency when Twitter is involved.

In February, Rep. Pete Hoekstra, R-Mich., found himself in a bit of hot water when he updated the public on his travels through Iraq and Afghanistan.

"Just landed in Baghdad," the congressman declared on Feb. 5 at 9:41 p.m., The Associated Press reported at the time.

Later that evening, he disclosed more details: "Moved into green zone by helicopter, Iraqi flag now over palace. Headed to new U.S. embassy. Appears calmer, less chaotic than previous here."

Hoekstra said he wasn't in the wrong, pointing out that other high-level officials also tweet their travels.

But the episode led the Pentagon to review its policy, as it views such information as sensitive, The Associated Press reported.

Virginia State Senator Tweets Possible Defection

But he's not the only politician to have trouble with Twitter.

When his party came close to convincing a Democratic state senator to defect in February, Jeffrey Frederick, then the state's party chairman tweeted a tease.

"Big news coming out of Senate: Apparently one dem is either switching or leaving the dem caucus. Negotiations for power-sharing underway," he wrote.

The switch would have created a 20-20 tie in the state Senate, broken by the state's Republican lieutenant governor, The Talking Points Memo reported.

Frederick's tweet upset the upset. The Democrats read the message, mobilized and made sure the senator stayed on their side of the aisle.

Did Twitter Break Up Aniston and Mayer?

Pop crooner John Mayer didn't get into trouble for what he wrote on Twitter but rather that he was on it at all.

The U.K.'s Telegraph reported in March that the pair may have split, in part, because of all the time Mayer was spending on the micro-blogging site.

The rumor was never confirmed but the buzz prompted social media blog Mashable to use the Twitter tracking tool TweetStats to figure out the number of tweets he was sending a day.

Since February, it said he'd been sending about 7.4 a day. Not the volume of an addict, it said, pointing out that the break-up wasn't so much Twitter's fault as it was the lack of reported attention.

According to The Telegraph, in the aftermath of their break-up, Mayer tweeted, "This heart didn't come with instructions."

Job Hunter Jeopardizes -- Maybe Loses -- Offer With Tweet

One job hunter -- on the verge of employment -- ran into trouble with a potential employer after an unfortunate 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 my work," the applicant wrote, according to MacWorld.

But someone from Cisco was paying attention and wrote back, "who is the hiring manager. I'm sure they would love to know that you will hate the work. We here at Cisco are well versed in the Web."

The tweeter switched on the privacy settings after this message. So the blogosphere never learned the end to the story. But it led to much online speculation, ridicule and even a dedicated Web site, ciscofatty.com.

Tech Expert Asks for 'Do-Over' on Twitter

Sometimes, even the most tech-savvy of the technorati run into trouble online.

In March, New York Times consumer tech columnist David Pogue shared his personal phone number with a few too many people when he first started getting used to Twitter.

Thinking he was sending private notes to just a few Twitter friends, he let loose a message with his phone number included.

Imagine his surprise when he realized that he had sent the number to 21,000 Twitter followers instead.

Within seconds, he wrote in a column, he realized his mistake and followed up as fast as he could: "YIKES! I'm so sorry, that was meant to be a direct message. Have mercy… Please disregard my phone number!"

A follower recommended that he delete the post (which Pogue didn't even know he could do.)

But he said that the crowd was sympathetic. Not a tweeter called his number and one wrote: "You'll be ok. Folks are respectful when it really counts."