No captcha?

Hello,
I am learning programming and just discovered this website. But I am curious, how does it protect its users from spammers (people who post illegal or annoying things) without a reCaptcha? I thought clicking this blue box is required to prove that you are not a robot, can you please share any javascript that you use for this purpose?
Thank you and have a nice day,
Brian

Removing single-word posts seems to make the thread much easier to follow.
Array.from (document.querySelectorAll ("div.post > div.body")).filter (e => /^\S*$/.test (e.innerText.trim ())).map (e => e.parentNode).forEach (e => e.parentNode.removeChild (e))