I guess you're adding to my thoughts about facebook.
"I am not missing out on much."
On a more serious note, it seems that now there is facebook, people think it's appropriate to behave antisocially on the internet as it's a different environment to real life. In the end however, what happens on facebook deeply affects real life. "Unfriending" has become an issue to get angry about. I think people have the right to clear their friendslist due to not speaking to some people on them.
It appears people on facebook tend to friend each other not to be friends but instead to brag about how many people they apparently are friends with. (We some friends are actually friends).
Anyways, I hope your ex appologizes for what they have done as you obviously shared some nice memories. Please try and remember them and don't let them be tainted by the bad memories of break up. Life's too short to be filled with negativity.