In case you haven't heard, AOL and Yahoo revealed last week that their solution to the problem of spam email was to charge users who send email from an aol.com or yahoo.com address.

The charge won't be mandatory, however. Using a technology called Goodmail, AOL and Yahoo will prevent mail from people who pay the fee from being marked as spam. Users of the service must assure Yahoo and AOL that they won't email anyone who hasn't requested to be emailed. After paying the fee -- which could be as high as one cent per email -- and giving Yahoo or AOL an assurance, senders' emails will never be marked as spam in AOL or Yahoo's mail systems.

Great idea, right? It will stop spam, won't it? I mean, a financial burden is a disincentive to engage in a particular practice (cf. Oakland's new ordinance regarding litter, or charging companies for polluting), right?

Not really.

First, all the system does is remove a barrier. It doesn't impose new barriers for spam emails. AOL and Yahoo have blacklists for filtering out spam emails. All this Goodmail system will do is remove XYZ Corporation from the blacklist. Spammers will continue to come up with new and innovative ways of getting around the mail filters.

Second, the system creates a slippery slope: charging for emails. While it only applies to people who want to use it, the precedent has been set. Companies are now charging for emails. The Electronic Frontier Foundation's legal director, Cindy Cohn, warns:

Even email senders who just want to reach Dad@aol.com may eventually be in trouble. Once a pay-to-speak system like this gets going, it will be increasing difficult for people who don't pay to get their mail through. The system has no way to distinguish between ordinary mail and bulk mail, spam and non-spam, personal and commercial mail. It just gives preference to people who pay.

"Payment" is, in this system, a proxy for "not spam." The problem is that this isn't always true. Things that are not spam might not be paid for. Things might be paid for that are spam. There's plenty of wiggle-room for false positives (something marked as "not spam" that is spam and something marked as "spam" that's not spam). In any security system in which you're trying to restrict access to just the people you want, false positives mean that the system isn't working, and a dysfunctional system might be worse than no system at all.

We have lots of proxies in our society. "Race" often stands in for "poverty." "Wealth" often stands in for "virtue." The beauty of the Internet is that those proxies don't exist. Putting the Goodmail scheme into place would create a new one: if you have to charge for it, then it must not be junk. Free is bad. Costliness is good. Except, the Internet functions on being free. This is why people run away in droves from websites that require pay subscriptions (except for porn sites, because the demand for porn is apparently perfectly inelastic). As Cohn notes in her blog entry, being free is "a feature that has driven the digital revolution. It allows groups to scale up from a dozen friends to a hundred people who love knitting to half-a-million concerned citizens without a major bankroll."

On a philosophical level, charging for email is a bad idea. On a pragmatic level, it's a bad idea: it won't solve the problem of spam email (or spammers will go to other ISPs for free email addresses, or they'll write viruses to turn infected computers into zombie mass-mailers).