A 21st century test: What's a 'search'?

[Commentary] Even many who cherish the "original meaning" of the Constitution recognize that provisions drafted in the 18th century must be interpreted in light of changing technology. That is especially true of the 4th Amendment's guarantee of the "right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures." When the amendment was adopted, unreasonable searches involved physical trespass. But in 1967 the court ruled that the 4th Amendment was violated when federal agents affixed a wiretap to the outside of a telephone booth being used by a gambler. What mattered, wrote Justice John Marshall Harlan, was whether the suspect had a reasonable expectation of privacy. The framers of the Constitution could not have envisioned the cellphone, much less its ability to establish the whereabouts of its owner, but the language of the 4th Amendment to protect persons and "effects" will, as it so often has, adapt to modern life.