A few other reasons to care about privacy
- "I don't see any problem with personalized advertising. I'd rather hear about stuff that's relevant to me!"
- Price discrimination based on tracking is real. If you are the type who buys product A without shopping around much, a higher price for relevantly related product B is shown.
- Tracking happens whether you are shopping or not (). In drift net fishing, a lot of other animals get brought in (I think the old PGP manual uses this analogy); similarly, browsing unconnected to your shopping habits gets brought into records of your behavior online.
- Companies that know detailed information about you can manipulate you effectively, and the effect may not always be in your own interests (ice cream ads during late afternoon, when you're prone to snacking, for example)
- ad networks present ads that have infected visitors with malware. They have admitted that they cannot control this (see previous page links).