We all tall about the companies we work for with our friends, families even ransoms people in the pub and what we sat influences their opinion. Social media just magnifies what we are saying and announces it to a wider audience than attended. Both employees and employers need to respect this and be realistic about what they are doing.
I remember a case about three employee who were fired for uploading a video of them play fighting in their work uniforms. They took they employers to court and the judge overturned the decision as the video had 8 views! Lets not pretend that our opinions count that much and what we post goes instantly viral otherwise we wouldn't need sites like this.