Cell phones can be used to record events which could potentially be used as evidence to outsiders, they can also have components turned turned on remotely to allow guests to effectively attend uninvited.
I get that part, but Q is saying phone are left at door, meaing no recording capabilty, yet Q claims the know details of the discussion.
Insider spy? Someone who has been flipped? Yeah in some cases, not all.
Videoconferencing capture? In some cases. Surely the blackhats know NSA capabilities
Bugs in the room? old gumshoe technology? maybe
What if the point is the other way around? How does one know what happens to ones’ cell phone when it has had to be left outside the room?