Comments on: Porn gets spammers past Hotmail, Yahoo barriers

Junk e-mailers set up porn sites and use visitors to bypass defenses used by Hotmail and Yahoo to stop bot software from automatically opening e-mail accounts.

How about a timer for fix?

If a timer is associated with the Captcha picture which changes periodically (say 10 seconds) will that alleviate this problem so porn sites can not get timely typing to create a new account?

Just require Captcha graphics to send email!

It seams so simple. Just require the sender of any email message to interpret a Captcha graphics image before each email message is sent, kind of like a stamp. And only allow the sending of bulk email messages for paying accounts. That should put crimp in the spammers hose!

Even better, require Captcha image for delivery of email

When a sender of an email message is not listed in the recipient's list of valid email senders, the email system would automatically send a challenge email message reply containing a URL the sender would then have to click on to complete the challenge. The email would have the recipient's email address and name exactly as it was in the sender's email. The sender would have to have placed the recipient?s email address in their own list of valid email senders to receive the challenge message. This challenge would be sent regardless of whether the email was sent to a valid email address to avoid successful probing. Bulk email to addresses that do not list the sender as valid would be discarded without generating a challenge. Only when the challenge was successfully met would the message be delivered to the recipient. Unless the recipient adds the sender's email address to their valid email address list, the sender would have to meet the challenge each and every time a message was sent. How's that for eliminating spam but still letting your long lost buddy's email get through!

[sebastiannielsen]

Watermark is the solution....

If you own a site named "www.myforum.org"...
Render a red text repeatedly in the background of the captcha: "www.myforum.org". Then you render the black CAPTCHA code above the red text.
Make sure the watermark text shines thru the black text a little, so it becomes VERY hard to remove the watermark text without damaging the captcha text so severly thats its impossible to read the captcha text....

Another idea is to make up the captcha text with the watermark text... Maybe it gets too hard to read the captcha text, but experiment with the spacing, to get well readibly.

(captcha text = the code the user is supposed to enter)
(watermark text = your site's name)
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The offending porn sites will get very bad reputation for stealing captchas.