The Internet provider reserves the rights to control my e-mails because it owns the network that I use. Even without going so far the idea of right to control the e-mail based on the ownership of the net is rather strange. It might happen that the letter contains dangerous materials or nasty pictures ordered from Amsterdam. We can go even further. Letters and e-mails are only means of transport of our thoughts.
Some people have really bad thoughts about employers and their property.
I imagine how many factories we can safe from the attempts of mad employees. Probably all of us would answer no to these questions. The big race has just started - it is rather likely that minds are the target. Moreover, if you do not download nasty pages and write wrong things about your employer you are safe. That might be true but there are two factors that disserve consideration.