It depends on the situation. If you are a mother, and concerned about something, sure I'd check it, but dont ready every single email, just something that might be suspicious, and I would never do it behind there back.

My ex-boyfriend had my password for some odd reason and he told his best buddy it, and his buddy hated me, so he went on my msn and said some mean things to good friends of mine, and changed my screen name to an AWFUL name, which I cannot repeat...just shows the immaturity of some people.