Posted by Jimi-Carlo Bukowski-Wills on 09/21/05 12:12

You could also try this:

on your guestbook form have another input (type=text) into which the user
has to type a code... this code they must read from an image, which you can
create easily in php. Whilst creating the form page, generate a random
number and save it in the $_SESSION variable. Also use it to make your
image. Then, when somebody tries to submit a message, check that the code
they typed matches the code you saved into the session variable. If so,
fine, if not, spew out the form again, with their message and a new random
number so they can try again.

If you were feeling really brave, you could write each digit of the number
in a different font and colour, give them random horizontal and vertical
jitter, and try putting random coloured lines over the top!

Jimi

----- Original Message -----
From: "Greg N." <yodel_dodel@yahoo.com>
Newsgroups: alt.comp.lang.php,alt.php
Sent: Friday, September 09, 2005 11:18 PM
Subject: Re: guestbook spam


> WeeWillyTonka wrote:
>
>> I have a guestbook that keeps getting spamed...
>
> 1. Keep your form pages off the search engines. Put a <meta
> name="robots" content="noindex,nofollow"> whereever you offer a form, like
> feedback pages, guestbooks, etc. If the robots don't know about the forms
> pages, the spammers won't easily find them, short of running their own
> crawler.
>
> 2. Change the form page's URL every other month or so. It takes some time
> for the spammers between harvesting forms pages URLs and using those URLs
> in their spam bots. By changing the URL regularly, you stay ahead of the
> spam.
>
> --
> Gregor's Motorradreisen:
> http://hothaus.de/greg-tour/

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