Only allow captcha solutions from IP which the captcha was given to

[darxus]

Title
Only allow captcha solutions from IP which the captcha was given to

Short, concise description of the idea
Only allow captcha solutions from the IP which the captcha was given to

Full description of the ideaIf you're not aware, there are a number of sites that will get humans to solve captchas for you for $2 per 1,000. I suspect the way lj is

Comments

+1

[lady_angelina]

Especially on the point regarding dynamic IP addresses. I can't tell you how many times Gmail has alerted me to "suspicious activity on my account" all because my BlackBerry's IP number was changed while I was in the middle of checking my email from it. While ReCAPTCHA won't work on BlackBerry so this makes it a somewhat moot point for me, it might be the case for other folks who are trying to pass the ReCAPTCHA test.

Re: -1

[pauamma]

Agreed on all points. (Also, does anyone know how many CAPTCHAs does reCaptcha send to LJ within the lifetime of a single CAPTCHA, and how many unique CAPTCHAs does it hand out altogether in that interval? I'm curious about the probablity of a collision.)

Re: -1

[lady_angelina]

To be honest, most of what is being passed to ReCAPTCHA (it seems to be piped through www.google.com/recaptcha/api whereas it didn't used to be) these days is just jumbled nonsense. Here's an example. So I guess that, if I understand your question correctly, that would take care of potential duplicates. =P

*Misses the days when ReCAPTCHA used to send two actual real words, whether related to each other or not, instead of... nonsense ones*