In 2013, Justine Sacco, a thirty-year-old senior director of corporate communications at the media and Internet giant IAC, boarded a plane from New York to South Africa. Along the way, she tweeted a few mean jokes, then on a layover in Heathrow, tweeted: \u201cGoing to Africa. Hope I don\u2019t get AIDS. Just kidding. I\u2019m white!\u201d She had only 170 followers, but by the time her plane landed in Cape Town 11 hours later, the tweet had circled the globe. The hashtag #HasJustineLandedYet was trending on Twitter and tens of thousands of angry people had tweeted back at her. Totally unaware, Sacco was blindsided by the media storm she encountered when her plane touched down. She apologized profusely, but it didn\u2019t matter \u2014 the story didn\u2019t die. She was let go by her employers, and had a hard time finding a job after. Unless you\u2019re Donald Trump, what you say on social media can get you fired. But as an employer, when exactly can you \u2014 and perhaps more importantly, when should you \u2014 take disciplinary action against an employee for unsavoury social media behaviour? We talked with Kseniya Veretelnik, a lawyer at Loranger Marcoux in Montreal, to find out. The Sacco story is Veretelnik\u2019s favourite cautionary tale to illustrate the ramifications of social media. She suggests sharing it, or stories like it, with employees. \u201cWe hear the argument\u2026 \u2018Well, I thought it was private. I thought I just had a couple of friends.\u2019\u2026Even if you have only a few followers, content can be shared, and once it starts being shared, you can\u2019t take it back,\u201d Veretelnik says. Our private lives are increasingly becoming public. Twenty years ago, talking smack to your friends rarely posed a threat to your workplace, but these days, an employee\u2019s circle of friends can extend to a network of thousands, and anything posted on social media can be picked up and shared with millions. So, what should you do if your employee defames your company, shares confidential information, or make highly offensive, racist or misogynist comments? What if they harass another employee? Does the offending post have to go viral before you can take disciplinary action? As is often the case in legal matters, Veretelnik laughs that the answer to pretty much any of these questions is: It depends. In the case of employee harassment, you have an obligation to act on it, but otherwise there are no hard and fast rules when it comes to social media. By and large, an offending post must damage the reputation, or have the potential to damage the reputation, of the organization. If a post is in poor taste but has no impact on the workplace, the employer must respect the employee\u2019s privacy and right of expression. Social media blurs the lines a little in that it\u2019s harder to decipher where the workplace ends and personal life begins, but in general, what an employee does in his or her private life is his or her business. Veretelnik suggests employers take the following four steps: \tCreate a social media policy that details what social media means and what it extends to \u2014 there are more and more platforms \u2014 it\u2019s not just Facebook and Twitter anymore. Explain what kind of conduct is inappropriate and prohibited. The policy should also be personalized depending on the needs of your organization. \tUpdate all your other policies, such as confidentiality agreements, to include social media. \tWhen you encounter something problematic on an employee\u2019s social media feed, consider all the facts before making a hasty decision. Make sure whatever content you found has a clear connection to the workplace. It must be clear from the individual\u2019s social media profile that they are an employee. It also matters how many people will see the post. If the individual\u2019s account is relatively private (of course, there\u2019s no such thing as a totally private account) you may not be able to do anything. \tVeretelnik says that most employers have no idea what their employees are doing until it\u2019s on the front page of the paper. Keep an eye on what employees do online, but bear in mind that it\u2019s a double-edged sword. You might find things that you don\u2019t want to see that you can\u2019t act on. And only monitor social media behaviour in a legal way. Never create a fake profile or ask employees to provide you with information on their coworkers.