Break the device for a while. Give the "cheating" player a slow disease, so it 'seems' there was no problem but there will be consequences. Break the timeline. Everything starts going seriously haywire because of that one little touch etc. Maybe break your story for awhile but give'm a...
I can't believe I started gaming three decades ago. Sadly, the last few years I've been out of contact.
Have particularly played ShadowRun and DnD over the years, with a few others systems here and there. Love to find a new game or games :D
Quiet thread looks like...