It's also worth mentioning that Microsoft is, to the best of my knowledge, relatively scrupulous about keeping their telemetry data anonymous. Meaning that they're still being way less sketchy about this stuff than your average e-tailer, or mass market retailers like Wal-Mart and Target.

Except they are taking things like file names, e-mail headers, recipients, and even in some cases they are taking documents. The recent recommendation from them was as follows:

From - https://www.theregister.co.uk/2018/11/16/microsoft_gdpr/

"...[Microsoft] also recommends simply not using the web-only version of Office 365, or SharePoint Oneline. And it recommends periodically deleting the Active Directory accounts of VIP users and creating new accounts for them so that the diagnostic data associated with those accounts is eventually deleted."

Seriously, we should be deleting and recreating accounts in our own fucking domain to keep the data anonymous? Why is that on us?

They have you AD account info, and diagnostic data directly tied to it. There's no anonymization going on here at all. They're gathering it recklessly.

Also from that link:

"Much of what Microsoft collects is diagnostics, the researchers found, and it has seemingly tried to make the system GDPR compliant by storing Office documents on servers based in the EU. But it also collected other data that contained private information and some of that data still ended up on US servers."

Do you have a cite for how well they anonymize? Is it as strong a position as Apple (e.g. differential privacy)?

The problem is that a lot of their telemetry and data comes from the Windows Insider program. These are the users who get the releases early to test. I don't know an average person who would want to test new features early, and deal with buggy releases and more frequent updates. And I don't know any power users who would even try to use an insider build for daily production use, since it's going to interfere with day to day work. If I had to guess, the insider builds are put mostly on people's secondary computers, where they will log in and fiddle around, then go back to doing what they really need to on a stable build. Seems like their data is biased from the beginning to me.

Power users are already the only ones opting out. Maybe that's why it has become what it is.

Good point, I spent a few hours tweaking win10 exactly to my taste and telemetry was one of the first things to go.

How much time have you spent making sure what you set hasn't been overridden after an update? Once I realized it was going to be a life-long battle, I swore off all MS products for personal computing.