Ever vented about a bad day at the office online, or wanted to tell the twittersphere how much you hate your boss? A Fair Work commissioner is warning workers to be careful about their tweets.

Leigh Johns says using social media to discuss your job dissatisfaction is a one-way ticket to unemployment.

“Unless you are an employee who made a New Year’s resolution to #losemyjob, using social media to telegraph to the world your dissatisfaction with your work, your job, your co-workers, manager or boss is #dumbbehaviour,” he said in an article for The Australian Financial Review.

According to Johns, there have been 309,712 Instagram posts from users with the hashtag #boredatwork, 30,685 #hatemyjob photos and 1068 #hatemyboss posts.

On Twitter there are hundreds of tweets every hour from users who hate their jobs.

“No matter what your security settings are, or how much you trust your friends on Facebook or followers on Instagram, there is always a risk that what you post on social media will become known to your employer,” Johns says.

“Every year the commission hears and determines claims of unfair dismissal, where the employee has been sacked because of their activity on social media. In most of these cases the employee claims they never intended or expected that their employer would find out about their online activity.”

Unfortunately for these employees, the very nature of social media is that it’s social, posts spread and employers do find out. Online, nothing is private.

Manager of digital research and analysis at SR7, Anthony Mason, told SmartCompany employees need to consider whether or not it’s a good idea to add colleagues on social media.

“Employees should genuinely consider the merit in adding colleagues, particularly more senior colleagues, as friends on social media networks. Whilst it is generally unwise to discuss personal aspects of work on social media platforms, that risk is compounded when connecting with workplace online communities,” he says.

“The volunteering of key professional details including employers and job titles also serves to pinpoint employees that make imprudent comments about work.”

Mason says many people have their workplace listed on either Facebook or Twitter, but don’t think of the consequences of this.

“People should be discerning about the information they volunteer on networks. I personally don’t have my workplace on my Facebook,” he says.

“Some people put it down simply because Facebook is telling them to. It prompts them, saying their profile is incomplete, and this encourages people to include information they mightn’t have otherwise.”

In one FWC case, an employee was fired after publishing insulting, threatening comments about a colleague online from their home computer. The FWC upheld the termination.

“The employee had a grievance about how they were being paid, but airing their frustration on Facebook cost them their job,” Johns says.

“In another matter an employee claimed he thought his Facebook profile was private, but offensive and disgusting comments (which were likely to cause damage to the employer’s reputation made their way back to the employer.”

In this incident the employee also lost his job and unfair dismissal case.

Mason says businesses need to have a social media policy, and ensure it is communicated to staff.

“The social media policy is first and foremost an educational document. The ideal social media policy is brief, aligned with other communications policies and effectively communicated across the breadth of an organisation. Businesses too often fall short in meeting these aims,” he says.

“If the policy is only wheeled out after an incident, the organisation will not effectively combat employee-driven reputational damage before the fact.”

Mason says social media training sessions are “invaluable” in teaching staff appropriate behaviour online.

“It also makes clear to employees that the organisation takes social media reputational damage seriously,” he says.

“’There should no longer be any doubt among the business community that the submission of harmful social media content is legal grounds for employee dismissal.”

Johns says employees are entitled to opinions, but need to be careful about where and how they’re expressed.

“Common sense should dictate discretion in the use of social media when it comes to events at work,” he says.

“The best way to avoid getting into trouble with your employer or possibly losing your job is #dontpoststuffaboutwork.”