Digression 3: Getting rid of spam
There is a simple solution to this problem—so simple that I am surprised nobody has yet implemented it. The solution is to put a price on your mailbox. Give your email program a list of the people you wish to receive mail from. Any mail from someone not on the list is returned, with a note explaining that you charge five cents to read mail from strangers. Five cents is a trivial cost to anyone with something to say that you are likely to want to read—but five cents times ten million recipients is quite a substantial cost to someone sending out bulk email on the chance that one recipient in ten thousand may respond.
What do you think of this proposal to get rid of SPAM? When I first read it I was dubious, but the more I think about it the more I like it! I guess we would just need something to request permission from sources not on your list that want to send e-mail that is not spam. What I like most about it is that you set your price and if you do nothing, you get all the spam, the full idea needs work, but sounds interesting. Read the full article for details.