On Wed, Jan 14, 2015 at 10:07 AM, Aaron Halfaker <ahalfaker@wikimedia.org> wrote:
For example, not collecting usage data about certain sections of our population (e.g. IE10 users where DNT is set by default) means that we don't know if our software works for them.

Note that IE 10 does inform you about the option and that it provides a means for toggling it:
https://skitch-img.s3.amazonaws.com/20120907-tu8m3msxk7sngf61188f8hxm7a.png

This is subtle, but still significant. It was cited by many participants in the debate about whether or not to honor IE10's DNT in Apache:

https://github.com/apache/httpd/commit/a381ff35fa4d50a5f7b9f64300dfd98859dee8d0
https://issues.apache.org/bugzilla/show_bug.cgi?id=53845