QSM reCAPTCHA Addon GPL Overview:
This plugin allows you to setup a reCaptcha for your quizzes and surveys. To protect your quizzes with a industry standard captcha solution, this is a must use plugin.
What is reCAPTCHA? reCAPTCHA is a free service from Google that helps protect websites from spam and abuse. “CAPTCHA” is a turing test to tell human and bots apart. It is easy for humans to solve, but hard for “bots” and other malicious software to figure out.