How many using Qubes have actually verified the keys and certificates to the extent suggested below?
"Use the PGP Web of Trust. Check the key against different keyservers. Use different search engines to search for the fingerprint. Use Tor to view and search for the fingerprint on various websites. Use various VPNs and proxy servers.Use different Wi-Fi networks (work, school, internet cafe, etc.). Ask people to post the fingerprint in various forums and chat rooms.Check against PDFs and photographs in which the fingerprint appears (e.g., slides from a talk or on a T-shirt). Repeat all of the above from different computers and devices."