Blocking third-party cookies does practically nothing to prevent such tracking. Web-bugs and supercookies, just for starters, are immune to that. Install Ghos

Blocking third-party cookies does practically nothing to prevent such tracking. Web-bugs and supercookies, just for starters, are immune to that. Install Ghostery to get all the low-hanging fruit - you'll probably want to tweak-up the settings from the default. There are still sophisticated trackers out there beyond what Ghostery can stop. For firefox the Request Policy add-on will give you very good control over that stuff, but it requires a "mechanic's" level of understanding to use without pulling your hair out. Frankly I am a bit surprised by your naivete - this sort of profiling is big business. Huge. I kind of thought that everyone on here on HN was aware of just how intrusive these tracker/stalkers were.