Why are Xbox-Live users so Anti-Semitic?

I had some friends on Xbox-Live that I have had for more than a year (I never met them in real-life). We were chilling out and playing some Halo, when we started a mini, racial discussion. 2 of the people in the group said they had mostly English blood, and one said they were Italian. They asked what I was, and I told them I am Jewish. I was instantly booted from the room, and without saying anything, all three of them blocked me from their friends lists.

In another incident, I was playing Left 4 Dead when a similar discussion came up. I told them, and one said “Die in a fire, Jew”, made a few racist jokes, voted to ban me, and I was gone.

Many events like this have been happening recently, even on more kid friendly games like “Uno”! What I want to know is, why do Xbox-Live users hate Jewish people so much? I was probably the most polite of the people there, and still people judge me from my bloodline (I tried explaining that Jewish can be both a race OR a religion, as I am Christan in faith, but that didn’t make any difference). What can I do to stop this?! Thanks, sorry for the more serious note, I just thought it had to be discussed…