Aha, mind piss is a venerable tradition heregoing back way before I joined. Basically occurs when two people post the same thought at the same time.
dictionary.mictoboy.co.uk/define/mindpiss/
(dictionary.mictoboy.co.uk/define/mindpiss/
Colonel Boris "...a desperate Buzzfeed imitation...",
Thu 29 Aug 2013, 2:30,
archived)