Users must pay to create a Zalo account
zalo requires users to text 5,000 vnd to open an account, 1,000 vnd if they forget their password, with the reason 'system busy'.
Tags : user authentication
The origin of CAPTCHA and reCAPTCHA
the word captcha is an abbreviation for 'completely automated public turing test to tell computers and humans apart' (roughly the automatic test for distinguishing computers and
