I call BS. While I agree that it is a cultural thing to not discuss this among friends and relatives locally, I know it is officially discouraged at the company I work for. Just for fun I polled some friends who work at large companies in big cities... without an exception, they say that they are officially not allowed to discuss salary or bonus structure with peers, and doing so can, and has, led to dismissal. The only people they are allowed to discuss this with is their direct leader and HR. They know their direct report's salaries, of course, as they are involved with reviewing them and adjusting their compensation.
Crikey, are you a naive asshole or what?
This is how real business works, harry. You don't know anything about that, having sucked the union's teat for so long.