Fun Fact re: "are you human" checkboxes/puzzles ...
... it takes a user, on average, 32 seconds to complete a CAPTCHA challenge.
There are 4.6 billion global Internet users.
Assume a typical Internet user sees approximately one CAPTCHA every 10 days.
This (admittedly) very simple back of the envelope math equates to approximately 500 human years wasted every single day ... just to prove we're human!
Oh, the Humanity!
Regards,
Dorian