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Now imagine sending a message to a mailing list that has a few hundred Spam Arrest users on it. You might need to spend an hour or two completing various tests. By design, there is no way for you to automate your response-that would violate the whole idea. Hotmail might ultimately want to verify that you are a human every morning, to be sure that you haven’t turned your account over to a machine.

Moreover, captchas based on visual puzzles discriminate against the millions of people who are blind or who have severe, uncorrectable visual impairment. Yahoo!, aware of this problem, has allowed blind people to register by providing their phone numbers: somebody from Yahoo! verifies their humanity with a phone call. But penalizing the blind with invasive workarounds is hardly an optimal solution.

If captchas really could close the spam spigot, then maybe we could accept them as a necessary evil. They won’t. That’s because captcha creators live in Western countries, where computer power is cheap but human time is expensive, so they’re creating tests that can be solved with a small application of human intelligence. But there are many places on the planet where human time is dirt-cheap. Spammers can circumvent the captchas by electronically farming the tests out to China, where a human brain can be hired for about 40 cents an hour. It would be a simple matter to sit a few hundred people down in a room and have them sign up for Hotmail accounts; they could probably register for 20 accounts an hour, or roughly two cents per account. That won’t stop the spammers.

Spammers who don’t want to hire Chinese labor can set up “free” porno Web sites, where the cost of admission is solving a captcha every few minutes. The spammer then writes a program that goes to Hotmail, signs up for an account, gets a captcha, shows that test to the porn fiend, and supplies said fiend’s response to Hotmail. Problem solved!

What’s worse, as computers get faster and recognition algorithms get better, captchas will have to get harder to keep pace. Today, you only have to recognize some words on a wavy background. In the future, the task of proving your humanity will likely entail a more convoluted test. If these tests are not nipped now, we are looking at a future where we spend a significant part of each workday proving to machines that we are not machines, too. As a human-and a humanist-I find this possibility deeply offensive.

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