This the one you're thinking of?: The story of the fake bomb detectors
They were all bogus. But despite this, some are still in use today - in Iraq at checkpoints, to guard sites in Pakistan, and at hotels in the Middle East.
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The fake "detectors" were little more than empty cases with an aerial which swings according to the user's unconscious hand movements, "the ideomotor effect".
Biting the hand that feeds IT
