This is a reference to the video that got JFK shot where he discusses the vast and monolithic conspiracy that we're up against, an enemy that relies on covert means, infiltration by night rather than invasion by day.
https://www.youtube.com/watch?v=zdMbmdFOvTs
Combine that with Q's post about the stipulations for justifying denying habeus corpus which demand that an invasion be taking place, and you have the legal grounds required. Infiltrators ARE an invading force and SHOULD be denied habeus corpus during this time of war.