In the case of Steven Dewayne Bond v. United States in 1999, the Supreme Court ruled on whether a law enforcement officer's physical manipulation of a bus passenger's luggage to determine its contents constituted as an illegal search under the Fourth Amendment. The defendant, Bond, was traveling by bus when an agent boarded for routine immigration and narcotics check. The agent squeezed soft luggage that passengers placed in overhead storage bins; upon squeezing Bond’s bag he felt a "brick-like" object which turned out to be methamphetamine. Bond was charged with federal drug crimes but argued that his conviction should be overturned because it relied on evidence obtained through an unconstitutional search. The Supreme Court agreed with him in a 7-2 decision stating that physically probing or manipulating personal items constitutes as searching and requires reasonable suspicion under Fourth Amendment protections against unreasonable searches and seizures.

In the dissenting opinion for Steven Dewayne Bond v. United States, Justice Breyer argued that the majority's decision to uphold Bond's conviction was based on an overly broad interpretation of Fourth Amendment protections against unreasonable searches and seizures. He contended that a bus passenger would reasonably expect some touching by other passengers or bus employees in such close quarters and thus, the physical manipulation of Bond’s bag by law enforcement did not constitute a search under the Fourth Amendment. Furthermore, he pointed out that there were no signs indicating private areas where bags should not be touched nor any explicit rules about handling others' luggage on buses. Therefore, he believed this case fell outside traditional expectations of privacy protected under constitutional law and disagreed with overturning Bond's conviction.