I've had this question for a long time, and now rewatching limitless it came up again. Why are the FBI so bad at their job? When Brian has to steal the NZT files he makes a bunch of different videos for himself. So we know the apartment was bugged, but you could say Sands removed them all, if you also assume the FBI didn't replace them, so they heard Brian making the videos where he describes his crimes to himself. But youre telling me Mike and Ike never saw anything? I mean there was a even a moment where Ike stood directly behind Brian moments after he finished watching the video! But not once did they hear or see a single thing? Does anyone have an actual explanation for this, or did they just make the FBI INSANELY incompetent for the show?

Edit: To be clear to everyone I'm talking about the fictional TV show FBI, not the actual fbi.