I used to do sysadmin work professionally, and I still do it personally (I have a Linode
VPS) where I host my personal e-mail, website, jabber server, and personal e-mail of family members. It's just one of those things that as a geek a lot of us end up doing.
One of the unspoken golden rules of trust was this: don't fucking read other people's e-mail. Period.
Now I do information security, where I keep my employer's network safe. This includes both external, and internal threats - such as domain admins going rogue, and abusing their powers (I've seen it happen, and wrote up the incident). It really bothers me that 1 out of 4 "IT Professionals" are unprofessional enough to violate the trust that has been granted them.