There is now legal precendent for service of a subpeona or notice over social media.
(OK, it was over Facebook, so bad example, but still ...)
............
Other posts: https://community.isc2.org/t5/forums/recentpostspage/user-id/1324864413
This message may or may not be governed by the terms of
http://www.noticebored.com/html/cisspforumfaq.html#Friday or
https://blogs.securiteam.com/index.php/archives/1468
