Time and a gain Fulcrum Agents find their way in to the Buy More and then disappear. The latest was Lt. Mouser who along with Ned set up the whole hostage rouse to flush out who ever Sarah and Casey were protecting. Then there is Jill, and Leader, and guy at the Opera House in "Chuck Vs the Fat Lady" who crushes the chip with the fulcrum agents on it. These and so many more examples would have not only raised red flags but fired off sky rockets over Buy More and Chuck.
This leads me to believe Fulcrum is run by a group who can only be described as dumb asses.