[bertil]

iamsalman offers a great response. Legally (and conceptually) there is the idea of a collection, a compilation being valuable in and on itself: this has been enforced to prevent people from selling phone books and TV programs without paying the original ‘compilers’, phone companies and TV stations, not as operators but original authors of an exhaustive description. Collecting changes useless information into, anecdotes, into a usable product: that’s the whole point of those companies, they (presumably by contract) guarantee a return rate that makes them economically sound; that changes the nature of ‘looking around’.

This idea is essential to all the creep factor around Google’s recurrent controversy: the problem is not taking street pictures, but guaranteeing that any house can be seen by anyone; it's not to murmur in your boss's ear ‘that’s the sub-commissioner in grey’ but potentially matching anyone’s face to their full public history. This is what made every page of a phone book precious, and every post-it with a phone number on it worthless.

[maxerickson]

U.S. law has moved away from that idea:

http://en.wikipedia.org/wiki/Feist_v._Rural

But it should still be straightforward to make laws saying that the tags on a vehicle are a particular type of information and then restrict the way that businesses are allowed to use it.

[bertil]

Indeed on the copyright of collection -- which as a fact was abused; but not the change of nature of the information.

I really don’t think that you can make enough information particular enough to get away with disanonymisation techniques: you standing anywhere in a city, with a block accuracy is enough to identify most people on a transport map; even whether you like a handful of movies, and in what order or when you saw them is enough to isolate individuals from a VoD database.

[maxerickson]

A company can make use of the observations without aggregating them. For instance, if they have a documented interest in a tag, I don't really have a problem with them disseminating it to their vehicles and checking it against live scans.