Suspecting that we're up to something is one thing, actually knowing what we're up to and where they need to be is another ballgame.
If we're smart and stealthy, we can slip in, empty the bank, and leave with none the wiser 'til morning.
Of course, we should be careful about using Brilliance's ECM all the time. Sooner or later someone'll notice when a lab drops out of contact. Say one of the guards was doing a online chess game with someone else, and they notice that there's been no reply in awhile...