Absurdly simple anti-spam script...

[RichardM]

...but will it work? It's so simple I'm embarrassed to post it, but here's what I did.

Here's a contact page here.

The visitor picks a random four digit number ($randnum).

A few fields later, they are asked to add seven to it ($haha).

The script pops an alert and exits if $haha doesn't equal $randnum + seven:

PHP Code:

if ($haha != ($randnum + 7))
{
echo "
    <script type='text/javascript'>
        alert('WRONG ANSWER! USE THE BACK BUTTON TO TRY AGAIN.');
    </script>
    ";
exit;
} 


This is placed before the mail processing section.

I mean, seriously, could something this stupid actually work?

Best,

Richard

[RichardM]

Or, if you have a landing page named "error.html" for failed validation attempts...

PHP Code:

}
$validationOK=true;
// get rest of variables first and validate them, then add
if ($haha != ($randnum + 7)) $validationOK=false;
if (!$validationOK) {
  print "<meta http-equiv=\"refresh\" content=\"0;URL=error.html\">";
  exit;
} 


Richard

[sam]

When a spammer's program visits your websites page, it will check every pages that you link to for email addresses. So to avoid these all you have to do is link to this page so that whenever a spammer's program scans your page, they will be confused into this one.

To link to this page, just use this simple code:

 Fight Spam! Click Here!

[bod-jack]

One of the best way to prevent automated web robot tools and spammers from taking advantage of your forms and scripts is by using a captcha image.

[RichardM]

I don't care much for captcha images. Robots can be programmed with OCR capabilities, and the captchas have to get so hard-to-read that humans also have problems with them.

I'm building a site that incorporates code based on what I described here (Fairly decent spam-stopper form) that eliminates the need for captcha images, and in fact uses the concept as a honeypot to trap bots.

Best,

Richard

[bod-jack]

I think captcha is a completely automatic public Turing test to tell computers and humans apart—is a test that humans can pass but computer programs cannot; such tests are becoming key to defending e-commerce systems. By using a Captcha, for example, IT systems can permit only real people—rather than a spammer's script—to create a free e-mail account.
And I think it's not very hard to read that captcha.