[thelist] CAPTCHA

Bob Meetin bobm at dottedi.biz
Sat Aug 8 23:00:08 CDT 2009

Hassan Schroeder wrote:

> On Sat, Aug 8, 2009 at 6:38 PM, Jeremy Weiss<eccentric.one at gmail.com> 
> wrote:
> I've seen CAPTCHAs that sucked, yes, but personally I'd be more
> inclined to just go with the "what's 2 + 2" question approach rather
> than stretch too far into interpretation based on what may not be a
> shared worldview.
> I know I shouldn't but can't resist. I regularly misread captcha - 
> really detest them. However, simple math if fairly universally 
> understood and works.
Side note - I'd swear that with Craigslist I've posted ads and if I get 
80% of the characters right, they go through.

> If you want to take it to level 2, it'd be pretty easy to use 
> imagemagick/convert to display two very readable (not pop art) images 
> as numbers.
% convert -background white -fill black -border 5 -bordercolor white 
-pointsize 30 label:'2 + 7 = ?' math.gif

Program in:
$result = $var1 + $var2
% convert -background white -fill black -border 5 -bordercolor white 
-pointsize 30 label:'%var1 + $var2 = ?' math.gif

That being said in general I prefer if possible using techniques that 
prevent spammers/spambots from filling in forms by addressing their 
repetitive behavior patterns. Also someone (can't find the email) made a 
super suggestion regarding placing a "administrator use only" field on 
the form and if filled in, deny the submission.

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