US v. Vaughn, decided 11/29/2012, 4th Cir.
After being stopped for travelling 79 in a 70 miles per hour zone. In the vehicle, the Officer observed four cell phones in plain sight and a passenger who acting normally but was exhibiting "high levels of nervousness" -- he was shaking and breathing heavily with trembling hands and the officer "could see his heart beating through his shirt." (emphasis added by me, to highlight asininity). In addition, the driver and passenger gave conflicting answers about where they were going. After a somewhat prolonged questioning for a speeding stop, a dog arrived and detected drugs.
The Court decided that the prolonged stop was acceptable due to the nervousness, cell phones, and conflicting stories.
The lesson to be learned is that, should you choose a career in drug trafficking, stay calm. We can also learn that criminals generally wear over-sized clothes not as a fashion statement, but to thwart the superhuman observation abilities of the police.
Another take on this case can be found here.