DC540 started after Defcon 26, in my then hometown of Fredericksburg, VA. In February 2018 I moved to Northern Virginia (Stone Ridge) and continued hosting monthly DC540 meetups there. A number of us communed together at Defcon 27, and some of us will be attending Defcon 28.
Twitter: @dc540baab
Discord: https://discord.gg/2sw9kMK
Citadel: telnet citadel.dc540.org 23230
Citadel/Tor: o7trajwshusmnuj7chr7nmuflvc3orcrc5r3zt4mnawmperdxjqqqbqd.onion
Meetup: