It's pretty annoying that I have to create spam filters for Google Analytics to be useful. Every site I've installed GA on has required me to filter out spam. I don't understand why something isn't done about it at an engineering level. If site owners can set up filters against spammers, is it really that hard for Google to do it? Especially since they can see it across their accounts. Seems like it's the same type of issue that plagues email, yet Google seems to have that under control.