Meta is able to identify you by your browser ID, as this is linked to other data about you stored by Meta on your Facebook or Instagram user account.

When you visit our websites, the pixel establishes a direct connection to Meta's servers. The meta pixel are code snippets which are able to identify your browser type via the browser ID - the individual fingerprint of your browser - and to recognise that you have visited our websites and what exactly you have looked at on our websites. The Meta Pixel is a remarketing pixel implemented on our websites that allows us to target you directly via the Meta Network by serving ads to visitors of our websites when they visit the social networks Facebook and Instagram.