The fact that someone is capable of murdering people and hanging them up on a bridge has very little to do with your right to comment anonymously on a funny cat video.
On any video, blog post, whatever, someone could decide they would like to punish you for what you say.
People are not logical.
When I was 15 I had the police show up to my house because a 12 year old I was playing a game with lost and was furious for losing.
He made up a story about my friend and I threatening him and it finally took his father coming home to figure it all out and realize that his kid was lying.
His father called me and personally apologized, but he could have just went with it and I could have had problems.
I learned my lesson and make it at least a little harder to find out who I am on the internet.
People are not empathetic. Empathy gives a path to logic, once you begin thinking of others. His father called you because he respected your feelings in the matter. How much of him knowing who you were may have played a part in his decision to call you.
Unless you propose that some committee oversee and approve every use of online anonymity to decide whether or not it's legitimate and necessary, it does in fact have everything to do with your right to comment anonymously on a funny cat video.
Someone needs to set up an Internet wide "Creepy PMs" (/r/creepypms) website, so women (and others) can show just how many disturbing contacts they get every day.
http://www.jwz.org/blog/2011/09/bodies-hanging-from-bridge-i...