While I feel we should all treat Google with skepticism here, I didn't realize they (and so failed to acknowledge) that Homebrew was attempting to remedy that, so I apologize for speaking out of turn.
Add a feature where users can opt-in for periodic reports to be uploaded as a private gist, and a link is transmitted to you. GitHub is already a trusted party where Homebrew is concerned, so the loss of privacy is minimal. Users control their own GitHub accounts, so they control of the permanence of the data you collect on them. You can use Google Forms to transmit the links, so your infrastructure is cheap-to-free. For bonus points, encrypt the links with your public key.
"We use the information we collect from all of our services to provide, maintain, protect and improve them, to develop new ones, and to protect Google and our users. We also use this information to offer you tailored content – like giving you more relevant search results and ads."
"When you visit a website that uses our advertising products (like AdSense), social products (like the +1 button) or analytics tools (Google Analytics), your web browser automatically sends certain information to Google... When you visit websites or use apps that use Google technologies, we may use the information we receive from those websites and apps..."
Collecting telemetry is reasonably, but it seems inappropriate for Google to get a copy and to be able to identify which of their users installed a particular piece of software from the IP address.
So yes. Running their own server would be much preferable.
Normally I would agree with you, I often chide people for inventing problems to solve. But it is a little different when it isn't a hypothetical as much as an inevitable future occurrence.
As for refrigerators, I am just as worried about people trying to fly drones around my house as I am about people flying drones around planes, yes. I have it on good authority that anyone with the funds can purchase access to 3D drone-generated map of my city, my house included. A gentleman here in town who replaces windows doesn't bother to measure them anymore; he just uses the drone photos.
We will always have to worry about intelligent, motivated people who wish to do us harm. Isn't that enough to worry about without being vulnerable to careless people, behaving unintelligently, who put lives at risk through their ignorance? Keep in mind, the latter group is much bigger.
The fingerprinting could be done server side. Their legal team could force browser vendors not to carry ABP or uBlock in the add-on stores, and GitHub to take down the repositories, meaning you and I could still find the source but not Average Joe. Your response to my comment about profiling ad blockers was entirely unconvincing.
You are placing more trust in this technology than it deserves, and I just think you should be aware; there are no silver bullets.
Edit: The browser fingerprinting could be done server-side. The add-on fingerprint looks something like, "were we able to load include this asset the add-on uses in an img tag?", so obviously requires interaction w/ the browser.
I don't see this as cheating, but we're talking about the company who convinced people "Rose Gold" was cool. If they told their customers it would be super for them to bring old iDevices back to the Apple store for recycling, I'm confident they would succeed.