====== Captcha ======
  * [[http://simplecaptcha.sourceforge.net/|SimpleCaptcha - A CAPTCHA framework for Java]]
  * [[http://jcaptcha.sourceforge.net/|JCaptcha]]
  * [[http://www.google.com/recaptcha|reCaptcha]]
  * [[http://www.learningjquery.com/2015/05/10-very-useful-jquery-captcha-plugins|10 Very Useful jQuery Captcha Plugins | Learning jQuery]]
  * [[aws:waf|AWS WAF]]