whois stackoverflow.feedback returns a phone number with a CNAM of STACK OVERFLOW, and the same address listed on https://stackoverflow.com/company/contact
whois google.feedback returns the phone number +1.1978600872, which is not a valid US area code last I checked. The address appears to be a PO box in Seattle.
facebook.feedback has the same bogus phone number and the same PO box as google.feedback.
myaccount.feedback (where they send you if you try to vote on anything, presumably other things too) has a residential address on Mercer Island, WA and a Google Voice number listed.
Calling the Google Voice number results in a voicemail where a person identifies themselves as "Jay" (presumably Jay Westerdal of Top Level Spectrum, Inc who owns the .feedback TLD)
Another thing of interest is that myaccount.feedback encourages you to login with Google/Facebook/Twitter/LinkedIn
> ICANN's core values are creativity, innovation, and respect the flow of information. The .Feedback registry is innovating and following those core values by allowing transparency with an independent review system that can be operated by anyone willing to sponsor a name. The .Feedback domain is different from all the other registries. It is human nature to fear change and innovation, this registry doesn't want to be in the business of selling just DNS domains like every other registry. We want to innovate!
(Innovation my ass...)
Also2, this seems to be the official page for the operation:
EDIT: Jay seems to be a big fish in the industry, so this is somewhat surprising.