It is UNLAWFUL for your employer to prohibit the discussion of wages between employees.
“Company policy” does not supercede national motherfuckin' laws. If someone gets fired for discussing wages within the workplace, it is clear and plain wrongful termination. Actually, it's more than that, it's the company breaking the law.
I see way too much corporate boot licking on this sub. Your employer, or you if you are an employer, cannot say jack shit about you discussing wages with fellow employees.