That is incredibly user-hostile. Google and Facebook would end up looking like the bad guys, and nothing would change.
"Facebook is a little slow because my ISP might be throttling, but I'm not sure, it could also be my computer"
"I cannot access Facebook at all because Facebook blocked my ISP"
Getting users pissed off at web services is not a good way to effect change. We need users on our side, so we can't have them think of us as crybabies.