Good point, for me it’s linking my cyberspace identity to my physical identity and having that sold on, stolen aggregated. Increasing my security vulnerability to phishing and identity theft
So you would agree if I store a cookie with a (randomly generated) ID in your browser to remember what you liked, what you bought, how you interacted with my website etc.? Also, I can sell this data to third parties and show personalized ads - all without knowing who you are outside of the web..