As professionals, you always hear people tell you that you have to be careful about what you post on social media sites. “It can ruin your career,” they say. Usually, we just roll our eyes and continue about our tweeting. “That will never happen to me,” we think. “I’m too smart for that to happen.”

In reality, behavior on social media has gotten quite a few people fired. Not to mention, a lot of their stories often catch the attention of the media. This means the reputations of these people are ruined on a mass scale.

It happens on Facebook, Twitter, Instagram, YouTube, and any other social site you might use. No outlet is safe.

Here are six stories about real people who got fired because of social media:

1. Fuming on Facebook.

About a month ago, a school bus driver in Georgia was fired for criticizing the school system on Facebook. A student who boarded his bus told the driver he was hungry because he was a few cents short for lunch, so the middle school didn’t give him any food at all. The driver took to Facebook and wrote:

“This child is already on reduced lunch [program] and we can’t let him eat. Are you kidding me? I’m certian [sic.] there was leftover food thrown away today. But kids were turned away because they didn’t have .40 on there [sic.] account. As a tax payer [sic.], I would much rather feed a child than throw it away. I would rather feed a child than to give food stamps to a crack head [sic.].”

His post was liked and shared thousands of times. While the driver might have believed in the importance of the issue, his action led to his firing. The school district has a policy against commenting on social media.

2. “Cisco Fatty” takes on Twitter.

Before even beginning his new job, this next guy lost it because of a tweet. After interviewing at Cisco Systems, a man wrote:

“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.”

A channel partner advocate for Cisco Alert found the tweet and replied:

“Who is the hiring manager. I’m sure they would love to know that you will hate the work. We here at Cisco are versed in the web.”

This unfortunate incident led to the man becoming known as “Cisco Fatty.” What a reputation!

3. Privacy breach on Instagram.

Posting photos can be just as detrimental to your career as words. Just ask the staff member from an assisted living home in Minnesota. He posted a photo of a resident on the toilet to Instagram. Talk about a breach of trust! Someone who saw the photo reported it and the staff member was fired.

4. Risky on Reddit.

One man from Texas was famous on Reddit for being a troll called Violentacrez. He had a reputation on the site for posting disturbing pictures of under-aged girls in bikinis and being offensive as possible. After having his real identity exposed in an article on Gawker, the man was fired immediately from his programming job.

With no job and a tarnished professional reputation, the man set up a PayPal account to accept donations from fans. Not exactly a reliable source of income.

5. Viral complaints on YouTube.

A viral video is the ultimate combination of people eating their words and the visual to go along with it. Hence, it’s incredibly easy to post a video on YouTube and get fired as a result.

A few years ago, four news reporters from Arkansas posted a few videos complaining about their jobs and the people they’ve met in their line of work. They filmed the videos at the news station and at actual news events, using the station’s equipment. Needless to say, everyone involved in the making of these videos was fired.

6. Blogging about work.

Blogs have gotten a lot of professionals intro trouble in the past. Take the English teacher from Pennsylvania, for example. She wrote a blog about her students’ behavior.

The blog was only intended for her friends, and she didn’t write about anyone specific, but it caught someone’s attention anyway. She called her students “rude, lazy, disengaged whiners” and became known for it. The school district suspended her with pay.

There are hundreds of other stories online about people losing their jobs over social media. Don’t be one of these people. Avoid posting anything offensive on social media. This includes things relating to your work and things relating to your personal life. You are a representative of your company and will be treated as such.

What’s the worst thing you’ve seen someone do on social media that got them fired?