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

Alternative >>311 upgrade of >>304 to summarize runs of repeated posts >>312-316,319-323.
((keyfun, handoff) => handoff (Array.from (document.querySelectorAll ("div.post > div.body")).map (e => [e, keyfun (e)]).reduce ((acc, [e, key]) => {
if (acc.length === 0) {
acc.push ({count: 1, bodies: [e], key: key})
} else {
const last = acc [acc.length - 1]
if (key === last.key) {
last.count++
last.bodies.push (e)
} else {
acc.push ({count: 1, bodies: [e], key: key})
}
}
return acc
}, []))) (e => e.innerText.replace (/\s+/g, ''), runs => runs.filter (({count, bodies}) => count >= 2).forEach (({count, bodies}) => {
bodies.forEach ((e, idx) => { if (idx > 0) { e.parentNode.parentNode.removeChild (e.parentNode); }})
bodies [0].parentNode.outerHTML = '<p style="border: thin dashed; text-align: center;">' + count + ' micro/pol/cels</p>'
}))