https://thenextweb.com/eu/2019/10/01/eus-top-court-says-pre-checked-boxes-for-tracking-cookies-are-illegal/

Europe’s highest court, the CJEU, has ruled that pre-checked cookie consent boxes do not provide the necessary legal consent needed for websites — TechCrunch reports.

Basically, when you open a new website, you need to manually opt in for non-essential cookies. If you don’t, the website doesn’t have any legal right to process your non-essential data. So if you see a pop-up saying you’ve received a cookie, with a pointless ‘ok’ button, then that website is breaking the law.