The bins article talked about things like "Installing a sensor in the bathroom so you know which gender the person has." Not to mention they'd connect things like which shops you visit and at what time. At any time a police officer could come along and say "We want all records you have on MAC address xx:xx". Quite a difference from websites tracking people.

The same problem exists with Google tracking - it's not that you know who's been to your site, it's that Google know every site you've been on, when you've been there, and what you did there.