In California v. Greenwood, 486 U.S. 35 (1988), the United States Supreme Court held that the warrantless search and seizure of garbage bags left at the curb would violate the Fourth Amendment only if the defendant manifested a subjective expectation of privacy in their garbage that society accepts as objectively reasonable (how convoluted is that?).
Although Justices Brennan and Marshall dissented, that has remained the law (mostly). Justice White, writing for the majority, did say that individual states might decide the issue differently.
In 2015, the Minnesota Supreme Court rejected an opportunity to decide that the Minnesota Constitution should afford greater privacy rights. Justice David Lillehaug wrote in his dissent, “Minnesotans have a reasonable expectation of privacy when they put their household waste in opaque bags and do what the government requires: place the bags in closed containers for collection, compaction, and conveyance to a lawful disposal site. I respectfully disagree with the majority that the Minnesota Constitution does not require a search warrant before law enforcement may seize and search such household waste… Since the 1980s, when Oquist and Greenwood were decided, the nature of household waste has changed. This is not your grandfather’s garbage. Vastly more household waste is being recycled and the digital revolution is in full flourish. For good public policy reasons, government encourages and often requires citizens to segregate and set out or deliver for recycling.”
So, how would you feel if the local newspaper sent a reporter out to look at your garbage? Sound outlandish? Well, it happened in Portland, Oregon. To see the reaction go here.
There is a slightly cynical view of the United States Supreme Court (and perhaps some state supreme courts), that in order to apply the 4th Amendment, the justices just ask, “Could this happen to me?” Well, it could—someone might just decide to go through the justices’ garbage, so maybe California v. Greenwood is no longer the law.