reCAPTCHA is a free service to protect your website from spam and abuse. reCAPTCHA uses an advanced risk analysis engine and adaptive CAPTCHAs to keep automated software from engaging in abusive activities on your site. It does this while letting your valid users pass through with ease.
Add Google’s reCAPTCHA noCAPTCHA to your website and protect your site from spam registrations and login.
This addon lets you choose which forms you wish to protect, you can decide to display the recaptcha field into the registration form, login forms and password recovery form, all with just a few clicks.