use of the /.well-known/dnt compliance property to indicate compliance with EFF dnt-policy

[npdoty]

The W3C's Tracking Preference Expression specification provides a mechanism for indicating compliance with a user DNT signal that doesn't require verbatim posting of a .txt document or any hashing/matching issues. It would be great if the EFF policy would also support indicating compliance by referencing a EFForg/dnt-policy URI from the compliance property in /.well-known/dnt.

That would make it easier to indicate compliance with EFF's policy as well as other policies, make it easier for Privacy Badger and other plugins to verify assertions of compliance, and could also resolve issues #22 and #23. It would require permanent, versioned URLs, which I think would be useful anyway (#25).

[cooperq]

Interesting idea, @pde I would like to get your thoughts on this. It definitely complicates the code paths in privacy badger but I am willing to make that tradeoff if we think this is beneficial enough.

[npdoty]

Ultimately, the idea is that it would be easier to implement checks if you were looking for a particular URI in a JSON file, rather than downloading txt files and comparing hashes, but yeah, at least in the short term, it would require doing an additional check in parallel.