How websites like Facebook are protected against bot without any captcha

Question

How websites like Facebook and Twitter are protected against bot during registration? I mean, there\'s no captcha at all on the signup form?

I want to create a signu

Answer 1

Since you don't want CAPTCHA, you can use Keypic - keypic.com - which is an invisible protection, no CAPTCHA needed. It's an efficient antispam method for any web form. Site users don't pass any tests which is good for the site as it improves the quality of the user experience and thus raises user engagement. The solution is a kind of an expert system which analyses the behaviour of the users and checks the databases, then makes a conclusion if the request comes from a legitimate user or a robot. BTW, Twitter and Facebook still use CAPTCHA for password verification which is a very disputable method in terms of efficiency of such protection.