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

Awesome code. Great size. Look thick. Solid. Tight. Keep us all posted on your continued progress with any new progress refactoring or optimization. Show us what you got man. Wanna see how freakin' huge, solid, thick and tight you can get. Thanks for the motivation.