A coworker of mine lost their job for something they posted on social media. Is this fair?

Thats tricky. My initial response is " no, its not fair" but after some consideration, I'd say it depends on the post. If it was pictures of all the money or supplies they had stolen from work- then DUHH. But if it was some evidence of activities or opinion that the workplace didnt agree with that had no bearing on their performance at work- then your friend got hosed and should look into a wrongful termination suit.

Depending on the post, yes. Inappropriate photos shared publicly effect can easily affect a company's brand. Millions of dollars go into creating branding a free public photo can very easily make all that go to waste.

This is not fair. It is a fact, however. Follow the rules, or be prepared to suffer the consequences.

If the employer has a defined Social Media use and practices policy and the post was done on company time, yes.

I do not believe social media plays a role in the workplace and should not be a part of an employees evaluation.

It very well could be unfortunately. Many companies have a social media policy that encompasses even personal social accounts as well as comments made from personal accounts. They need to look into the company policy and make sure that is stated.

I do think this is fair. Employees should realize they carry their reputation outside of work as well.

Maybe. Did they disclose personal or private information? Then yes. Was it bullying? Could be. Was it a conversation with coworkers about working conditions? Then no. Ask an attorney.

It depends on if it slandered the workplace.

No, not unless they were posting as institutional post.

yes, you are the face of the company and if you're posting things that breaks company code of ethics/policies then a company has every right to terminate or discipline the employee accordingly.