The Supreme Court ruled Tuesday that police could only use sniffer dogs to investigate a property and its surroundings if they first obtained a warrant. "A police officer not armed with a warrant may approach a home and knock, precisely because that is no more than any private citizen might do," Justice Antonin Scalia wrote for the 5-4 majority decision.

The decision upheld a 2011 ruling by the Florida Supreme Court suppressing evidence uncovered at Joelis Jardines' home with the help of Franky, a chocolate Labrador retriever with a strong record of sniffing out drug stashes. The Economist explained the justices' reasoning, the decision and its relevance to privacy laws more broadly:

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