Claims of DNT proliferation - Evidence?

Apologies if this has been documented somewhere in our discussions and I 
missed it, but I'm seeing more and more claims of the proliferation of 
DNT:1 online, especially outside the browser context. Can someone point 
me to a published study or paper that makes this clear and the sources 
for these signals? For my part, I'm looking into the extent to which DNT 
may or may not be sent today by specific Firefox add-ons. If we're going 
to consider this as a factor for which signals are OK and also as a 
justification for which path we follow, it would be helpful for the 
basis for this claim to be incontrovertible.

Received on Friday, 12 July 2013 19:01:30 UTC