Travis Megale is happily employed. A regular Facebook user, he knows how to use the site appropriately and what NOT to say or post. Unfortunately, many Facebook members do not. Job termination due to behavior on Facebook seems to increasingly be in the headlines. A recent survey from email security firm Proofpoint finds seven percent of organizations have fired an employee because of activity on social media sites. Another 20 percent said employees have been disciplined over social media activity. It's statistics like this that inspired Megale to launch his Facebook group "Fired because of Facebook."

"I'm a high school teacher so I have to be very mindful of what I post and I set up the group as a bit of heads up to my colleagues," said Megale. "People I had worked with in the past had made comments and posted pictures that could have easily resulted in their termination had they been seen by the wrong people. My hope is that the page will save a few people from making a silly, yet costly, Facebook mistake."

See also: Social media risks: The basics

In an effort to create awareness , the group invites members who have lost their job because of something they did on Facebook to tell their story. And tales of woe about a Facebook flub that lead to a lost job are revealed regularly. Recent examples posted on the group's Wall just in the past three days include one member who said "Fired for posting "F*** them nuggets" on a friend's page. I was a manager at McDonalds for 3 years. Gone!" Another poster writes: "Fired for not being 'the caliber of person that we like to hire. What you act like in your personal life reflects negatively on us as a company.'" (Related: 10 security reasons to quit Facebook)

While it may not make a fired employee feel much better about losing their job, there are reasons for an organization to monitor employee social media behavior and take action against things they deem problematic. It's often reputation and security concerns that an organization is concerned about when it comes to social networks, some of these include brand image and employee safety. (Also see: Keeping your company image safe on social media)

What are some of the red flag behaviors an employer might look for in their employees' online profiles? Here are ten mistakes users make on sites like Facebook and Twitter that could lead to unemployment.

Posting negative comments about your job or your company:

This might seem obvious - but for many people it's not. Some Facebook members feel the need to vent to friends and family about their job, or their coworkers, and are under the impression their profile is private. But this isn't always the case, especially if a user has failed to make their settings private, points out Tom Eston, host of the web site socialmediasecurity.com. Users need to be more mindful not only about privacy settings, but about keeping work-related rants to themselves.

"Just don't do it," said Eston. "Often someone will post something and then think, days later, maybe I shouldn't have done that. You can't blame the social network for that. People need to take more personal responsibility for what they post."

Even if you have your privacy settings locked down, remember that Facebook redesigns can cause settings to default back to public, making the content available for everyone to see until the user goes in and resets it. This was the case with a teacher from Cohassett, Massachusetts who was fired from her job in August after posting on Facebook that she wasn't looking forward to another year in the district. June Talvitie-Siple, who also had called the students 'germ bags' in another update, did not realize her settings were public after a recent Facebook change. She serves as a good reminder to check your privacy settings regularly.

Then there are those who are just plain forgetful. Like a woman who sounded off on her boss in a post that has now become internet legend. Unfortunately, that boss was also a Facebook friend who could easily view her profile.

The woman updated her status to read: OMG I HATE MY JOB!! My boss is a total pervvy (sic) w**ker, always making me do s**t stuff just to p**s me off!! W**ker!"

The boss responded: "I guess you forgot about adding me on here? " and ended with "Don't bother coming in tomorrow. And yes, I'm serious."

Defending your employer in an online dispute:

Just the opposite of flub number one, this can still be an offense, even if you have your company's best intentions in mind.

That's because even if you think what your saying is OK, you're not a public relations professional, and what you post could either be wrong, or even damaging to the company. Networking giant Cisco Systems specifically spells out in its social media policy that employees should not engage in any online debate about the company without specific permission.

"When an employee sees something negative about the company, they will sometimes want to defend their employer, who they are perfectly happy with," explained Christopher Burgess, senior security advisor for Cisco. "You can't do that in 140 characters in Twitter. What we've told folks is: Let PR do that."

Discussing private and/or security-related company matters:

So your company is about to acquire another and there is speculation about layoffs? Keep it to yourself. Posting this information on Facebook or Twitter is almost as bad as talking to the press about it. Even if you think you're just telling confidantes, there is no way of knowing where that information goes next, said Eston.

"Even if it's just a general context, certain information that might be confidential to a company should never be discussed."

Disguising your identity and pretending to be someone else:

You always want to be honest about who you are. Back to the point about talking about your company: Burgess says Cisco policy also forbids employees from disguising their name or identity in order to engage in debate about the company.

"The policy clearly states that it is unacceptable to use an alias," he said. "Employees should always state their relationship with the company from the outset."

Offering up too much information about your personal life and recreational activities:

Eston, who used to work in security for a large bank remembers a time when TMI on Twitter not only lost a job for someone, it prevented them from being hired at all.

The bank was conducting a background check on a job candidate, and found some less than desirable information.

"She had tweeted about how she hoped she would be able to get by a drug test, and her Twitter profile picture was her smoking a joint."

Posting questionable pictures:

Perhaps the most high-profile example of this is the case involving Patriots cheerleader Caitlyn Davis. Davis was fired from the team after Facebook pictures depicted her brandishing a Sharpie over an apparently unconscious man whose skin was covered in drawings and graffiti, among them two swastikas.

While the pictures and personal information you're posting might not be so egregious, it's probably a good idea to stay away from risqué photos as well as comments about your personal life that could cause an employer to pause and make a negative judgment about you. When using social networks, you want to put your best foot forward. Next time you post something ask yourself if it is something any one can see.

This story, "6 Facebook, Twitter Mistakes That Can Get You Fired" was originally published by CSO .