From: "simo" simo.sorce@xsec.it
Captcha on subscribe, it's becoming necessary :(
Joy. Captchas as usually realized are evil. They cannot be solved by blind people, and make it difficult for people using text browsers. Sound captchas (much rarer) still can have issues for the deaf and people without sound hardware. Captchas based on some kind of logical puzzle would be fine, but I suspect bots could end up learning the answers to them, since such puzzles are very difficult to generate automatically, and so you end up having to recycle them often. I suggest that something like HashCash or some form of PKI is going to have to be the solution.
--David.
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