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

>>23
$ python3
>>> ((22 + 22) // 22) ** (((22 + 22) // 22) ** ((22 + 22 + 22) // 22) - 22 // 22) * (22 + 22 + 22) // 22 - 22
362