Taxonomy of data

I haven't yet posted Parts II and III of our series on the idea of creating Creative Commons-type sharing licenses for personal information, but Bruce Schneier posted today on a proposed taxonomy of data, and I thought it was worth sharing now.  Although the taxonomy he's discussing is limited to social networking data, it's a helpful way to understand why it's so hard to come up with rules around personal information in general.Here is his taxonomy on social networking data:

Service data. Service data is the data you need to give to a social networking site in order to use it. It might include your legal name, your age, and your credit card number.

Disclosed data. This is what you post on your own pages: blog entries, photographs, messages, comments, and so on.

Entrusted data. This is what you post on other people's pages. It's basically the same stuff as disclosed data, but the difference is that you don't have control over the data -- someone else does.

Incidental data. Incidental data is data the other people post about you. Again, it's basically same same stuff as disclosed data, but the difference is that 1) you don't have control over it, and 2) you didn't create it in the first place.

Behavioral data. This is data that the site collects about your habits by recording what you do and who you do it with.

As I noted in my first license blog post, our idea is focusing strictly on "disclosed data," data an individual actively chooses to release.  It doesn't address the messiness around how the other types of data are being used and reused, except in that we hope explicitly talking about individual preferences around "disclosed data" can help all of us understand what really matters to people (and what doesn't) when they talk about the need for privacy around other forms of data.