I wonder if anyone has analysed the extent to which spam shapes the internet. In particular, I am thinking about the way that we have to trade off a degree of privacy to get effective protection. Google has excellent spam filters on gmail. My account there gets about fifty spams a day, and perhaps one is missed every two or three days. My daughter reports the same kind of efficiency from her Yahoo mail account. My guess is that part of this efficiency comes because you don’t “mark” something as spam; you “report” it. So, given that any significant spam run will hit hundreds of thousands of gmail users more or less simultaneously, a simple algorithm that says any message reported twenty times is spam will act more quickly than anything more formal, like spamassassin.
The logic of this is that we will tend more and more to give up the idea of personal servers, personal spam filtering, and so on, and huddle in groups to shelter from the giant whirling shitstorm that the public internet becomes.