I have a friend that had an ex boyfriend continually contact her for years after she stopped responding to his messages... From what I understand, his messages were really hurtful.. He just couldn't get over her moving on...

Also, you can always completely block her from your view. I know this can cause some... panic... at not being able to see what is going on... Feels like a loss of control... But at the same time, out of sight, out of mind. I had to do this with one of my husband's ex's. Not because she kept contacting him.. But because she was so buddy-buddy with all his family. I couldn't look at pictures of his 5 year old nephew on facebook without getting sick to my stomach because she posted on it. She had absolutely no boundaries (She's also European....), and his family didn't make it easy for me to ignore her even when we weren't friends on facebook... But now, it's muuuch better.... I rarely think of her (especially now that the wedding is out of the way.. I was terrified his mom had invited her or would ask us to invite her.. or something...)