A lie and/or fraud has been discovered and now is used as a warning to the public. The phrase possibly originated with US general store owners, who would nail counterfeit coins to their counters to ward off other counterfeiters. I can't believe I caught you in the act in front of all of my friends! Wow, another lie nailed to the counter! Oh, and he was cheating on me too. You all should consider this another lie nailed to the counter.