In order to prevent spam, cheating, bot and automated submition script attacks; a CAPTCHA must be presented to the user every time a particular form is performed and the user must successfully pass the CAPTCHA each time they fill out the form.
Activities and Situations need to implement CAPTCHA
There are some activities and situations that we need to implement CAPTCHA such as:
- User registration form.
- Forgot password or reset password form.
- Vote form, especially if it’s counted for a prize.
- Comment form.
- Register for free samples or products form.
- Form that allows a user to send email. For example: tell a friend form or share site form.
- …
And reCAPTCHA from Google is the best solution in the Internet, you can check out our tutorials How to implement Google Captcha (reCAPTCHA) with PHP or ASP.NET (C#) to stop bots from abusing it.
If you have any experience or other situations, please share by leaving your comment in the box below.