The First Amendment of the US Constitution protects people's rights to express themselves, no matter how controversial the opinion of one person is. In the workplace, most employees and superiors would prefer it if everyone would just behave like civilized people and refrain from gossiping about their co-workers. But culture dictates that there will still be people who will be fond of gossiping, especially if it's about fellow workers.
Just why do people gossip in the workplace? It's not exactly part of the job description, unless you're a gossip columnist at a magazine or newspaper. But gossiping is a very prevalent phenomenon in almost all workplaces. It creates a distraction and it divides people, which often hinders productivity and synergy. Due to the fractured social circles in the workplace, the mood and atmosphere becomes gloomy and this can dampen the enthusiasm of everybody else in the room, even if they don't have a direct involvement in the gossiping issue.
People gossip because humans, by nature, are social animals. Office workers have the wanton desire to communicate and share a conversation with each other and due to the lack of other interesting topics outside of what actually has to be done at work, the conversation oftentimes turns to behaviors and activities of other co-workers. This can include deviant or scandalous behaviors, and this can sometimes involve the boss. These people just can't help it. It's human nature to talk and since there aren't exactly a lot of things to talk about, some are suckered into the trap of simply talking back to their colleagues.
Insecurity is one strong cause of gossiping. Jealousy often takes a lot of forms and sometimes, this overreaching obsession with having to show how inferior another person is relative to someone else goes to an insanely scary level. Some people stop at nothing to put down and insult a colleague in an attempt to establish superiority. This level of arrogance and meanness must be assessed from the onset so that bad apples can be removed from the company even before they show the signs.
A company with a poor sense of camaraderie is easily corrupted by a gossiping culture. Because people hardly care about the feelings of one another, it is more likely that they can do things that can be hurtful to others. In a company where there is a strong concept of respect and mutual understanding between co-workers, synergy is reached, and all efforts become productive steps toward achieving a common goal. Ribbing and joking around isn't that bad, but once it goes to the level of defamation and wholesale indignation of a person behind his back, it certainly doesn't do anyone a favor.
Gossiping has no place in the workplace and the only way to police it is to understand how to establish clear rules in the company handbook that requires professionalism at all times. If all else fails, co-workers can probably police themselves and shame those in the minority who continue to insist on bringing down others. You can't force them to change, but social pressures always work.