[Modernman]

Otherwise, they would be perfectly within their rights to put video cameras in the ladies' restroom in violation of their female employee's right to a certain amount or privacy, etc.

That is actually quite legal, so long as you inform your employees of the practice.

[Barnstormer]

I see what you are saying - but, let's alter the sceanario a bit. Let's say the company requires physical work of their female employees and provide shower facilities they can use before they go home AND they put cameras in the female shower area. The female employees have a reasonable expectation that their shower will not end up on an internet porn site - their right to a certain amount of privacy did not fall out of their car when they entered company property.

As stated earlier, this issue is a bit more complicated than it appears and I believe it will go against the employers if they try to enforce arbitrary rules?