A federal court ruled that you can call out your boss on social media without getting fired - but that still doesn't mean you should

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It's still probably not a great idea to do this.

A Manhattan federal court recently ruled that a waiter who got sacked for bashing his boss in a profanity-laced rant on Facebook was illegally fired.

But as one employment lawyer cautions, employees shouldn't take this ruling as a signal that it's OK to start bashing their bosses on social media.

This case was very much the exception to a fairly hard and fast rule in most US workplaces, which is that you're less entitled to free speech surrounding work than you'd think.

So it's probably not best to put out a post similar to the one waiter Hernan Perez published on Facebook in 2011, in which he hurled a number of profane insults at his boss and his boss' family and ended with "Vote YES for the UNION!!!!!!!"

As the New York Post reported, what rendered the post "protected speech" was his call for his fellow employees to participate in an upcoming unionization vote. "If he had written only the profanity, there would be no legal protection," explains Harry Johnson, a partner in Morgan Lewis' labor, employment, and benefits practice group who wrote a partial dissent to the NLRB ruling. He said that the post fell underneath employee's legally protected right to express views about unionization to each other.

What's more, cursing at work was largely accepted and tolerated at Pier Sixty, the Chelsea, Manhattan-based catering company where Perez had worked for 13 years, which Johnson says ended up hurting its case.

The National Labor Relations Board ended up ruling 2-1 that that Perez's firing was unlawful. A ruling by the Second Circuit Court upheld that decision, as did a recent ruling in the Second Circuit Court of Appeals, as the New York Daily News reported. The courts ruled that the language would have to be more "opprobrious," or scornful, to warrant Perez's firing.

"In my dissent in the original board case, I thought the union statement was clearly protected but the degree of personally directed profanity in the entire Facebook post referencing the supervisor, his mother, and his family was just too much, so it caused that statement to lose its protection," Johnson tells Business Insider. "The Second Circuit disagreed, but did at least note that this was the 'outer bounds' of how far someone could go."

Ultimately, Johnson says it's still a good idea to exercise caution with your speech online - even if it pertains to unionization.

In most scenarios, at will employees in the private sector can be fired for any sort of speech - including political rhetoric.

"The takeaway for employees is that they have a fairly broad right to express views to each other on unionization, both pro and con, and on their wages, benefits, and terms and conditions of employment generally - but this decision marks the borderline of how far they can go," Johnson says.