It's not about stop. It's about showing that you tried. Do you think those "click yes if you're 18" are there to stop you? Nope, it's about protecting your ass

It's not about stop. It's about showing that you tried. Do you think those "click yes if you're 18" are there to stop you? Nope, it's about protecting your ass in case some concerned patent starts complaining. Sort of like official "I swear she was 18, officer".