One of my friends stalks me there. Meaning if I do not answer her calls, she will look to see if I am on Facebook doing something. If I am, she will be pissy that I did not pick up the phone for her. She even tells me what I was doing at the time--"I saw you playing Words With Friends and you didn't take my call." Also, if I happen to be on early in the morning, she will call me and say "Oh, I saw you were up so that's why I'm calling." I don't want to block her, I just want to be invisible in general.