I doubt there exists a company anywhere that's not monitoring email at least for spam and viruses.
There's certain times where it's not only acceptable but actually required to "violate employee's privacy" by searching their personal possessions - think airline employees, prison employees, etc.
Most companies will have some sort of auditing software on their critical servers to detect (and report) both unauthorized access but also unauthorized activity. I seriously doubt this is illegal in Europe. It's very difficult to take serious the position "my boss shouldn't know I logged into the production server and downloaded the whole database because 'I have privacy.'"
I'm an American, and it seems many of my countrymen think property rights should trump all other rights.