[Nick-Craver]

In the US at least (I can't speak for elsewhere), preventing this is illegal. Companies discourage it through various ways and it's practically an embedded culture thing at this point throughout the country. But: you cannot legally prevent it.

The National Labor Relations Act of 1935 is what you're looking for here - it provides employee protections for such discussions.

[JustSomeNobody]

Yeah, it's interesting. They can't prevent it, but if you do it, you can guarantee you'll be fired. They'll just eliminate your position for some other reason.

[phasmantistes]

You don't want to work for a company that operates that way anyway, if you can avoid it.