Parents got on MY facebook. Invasion of PRIVACY?

[pwnagekid]

Okay, so i'm almost 21, and in college. I pay for my own college and everything. Loans are in my name. My parents pay for NOTHING. Recently, my parents confronted my about a bunch of stuff which was somewhat true, but I could not tell them it was....because they would be very upset. Anyways, I was wondering HOW they found ALL this information out. I realized, they keylogged their home computer, and have been accessing my facebook for a while. I got on today, and had a bunch of checked notifications, which i did not check. This honestly, infuriated me. I do not believe they know that I found this out yet, but I changed my password. I am over the age of 18, and they did log onto my facebook account and invaded my privacy. Think I can get evidence from facebook, maybe IP address logs, and prove that they did this? I want comments, and ideas.