By using a system, you presumably agree to some terms and conditions you never read. Since I also never read them, I'm going to go ahead and presume that those terms and conditions state that any data or activity on said machine is and can be monitored by a sysadmin. If you don't want to be watched, you have to be the sysadmin.
Since I'm too noob to downvote, I thought I'd just chime in here and inform you that you are wrong.