"The fact that a person is not free to leave on his own terms at a given moment, however, does not, by itself, mean that the person has been 'seized' within the meaning of the Fourth Amendment," the court wrote in its unsigned decision. "In Florida, a person's right and liberty to use a highway is not absolute; it may be regulated in the public interest through reasonable and reasonably executed regulations." The judges found it was reasonable for Fanueil to set regulations for use of the road -- including the types of acceptable payment.

US Customs, a division of Homeland Security, is now using cash-sniffing dogs at airports for international travelers. A dog was able to detect one passenger's $400 in currency from among numerous travelers.