I saw that tweet and noted it because and it was similar to my theory that I had posted.
Halbermann is being monitored and and has been using another method of communicating with her sources.
Her Q train message was meant to warn her sources that Q people were on to their secret comms. Halbermann had to find a way to tell them without using their normal channels. 3 FBI and 1 DOJ were probably the sources
Tweet was by a Lisa something I think. Tweet called out Halbermann about her secret comms being watched. Was in one of the breads this AM round 9 or 10.