Data control has many aspects/axes:
* data: can you export it?
-o three major types of data; analysis may be different for each:
+++ private data: can others get out your personal/private data? can you take down old personal data that you've published? Potentially (like export control and the GPL) this can just be deferred to relevant national legislation?
+++ public, but personal, data: What about data that has been made public (for example, comments on a blog) but which are still in some sense identified with a particular individual?
+++ collaboratively created data: what about collaboratively created/owned data? e.g., a wikipedia page, or the implicit data of a myspace/facebook/linkedin personal network?
-o axis ranges from:
+++ can't export data
+++ can export data, but in an undocumented binary format
+++ can export data, but in an undocumented text format (e.g., CSV, XML)
+++ can export data in a documented format
+++ can export data in a standardized format
-o related: is there a source-available, freely-usable implementation of the service? (see, e.g., GPL v3's expanded system library exception for possibly analogous language)
- identity: do you control your identity? e.g., can I use '[email protected]' to make it easier to leave gmail, or tieguy.org/blog/ to make it easier to leave wordpress.com? How do technologies like openid play into this?
-o identity tied to service host (e.g., [email protected])
-o mixed: public-facing identity not tied to service host, but some services may still be (e.g., public uses [email protected], but I retrieve mail from http://gmail.com/ rather than tieguy.org/mail/)
-o identity not tied to service host (e.g., google hosted, public uses [email protected] and I use tieguy.org/mail/ to access the mail.)
* DRM: axis is nearly binary:
-o uses DRM or DRM-like controls to prevent distribution of data (i.e., flash video)
-o doesn't use DRM at all (http://live.gnome.org/FreeOpenServicesDefinition/DataControl)