The Fourth Amendment to the US Constitution protects people and their property from government scrutiny. It states: The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.
Translation: If officers of the law want to go rooting through your life, they first have to go before a judge and explain why. They have to establish that they have reason to believe that you might have committed a specific crime, or that they believe specific evidence of a specific crime might be found on or in a specific part of your property. They have to swear that this reason has been given honestly and in good faith.
Only if the judge approves a warrant will they be allowed to go searching—and even then, only for a limited time.
The Constitution was written in the eighteenth century, back before computers were invented. It stands to reason that computer files, whatever their contents, are our version of the Constitution’s “papers.” Data, meanwhile, is our version of “effects,” a catchall term for all the stuff that we own, produce, sell, and buy online.
In the centuries since the original Constitution Day, our clouds, computers, and phones have become our homes, just as personal and intimate as our actual houses nowadays. If you don’t agree, then answer me this: Would you rather let your friends hang out in your bedroom alone for an hour, or let them spend even just ten minutes alone with your unlocked phone?