Upholding the right ‘to be let alone’

When the Supreme Court ruled in 1928 that the government did not violate the Fourth Amendment to the Constitution by wiretapping a person’s telephone calls, legendary Justice Louis Brandeis wrote a prescient dissent taking a more expansive view. Justice Brandeis argued that the Constitution protects Americans “in their beliefs, their thoughts, their emotions and their sensations” and “conferred, as against the government, the right to be let alone — the most comprehensive of rights and the right most valued by civilized men.”

Fortunately, Justice Brandeis’ view of the Fourth Amendment ultimately prevailed in the Supreme Court.

Today, that provision’s protection against “unreasonable searches and seizures” provides a vital check on executive power to spy on us without a warrant. From bugging civil rights activists in the 1960s to examining individuals’ internet activity under the USA Patriot Act, the executive branch has repeatedly tried to extend the boundaries of its power and shrink our perimeter of privacy.

Courts have rightly pushed back. For instance, in the late 1960s, when the attorney general authorized electronic surveillance of members of the White Panther party without judicial approval, based on the government’s fear that they would attempt to “subvert the existing structure of the Government,” the Supreme Court unanimously rejected the government’s claim to a vague and unconstrained power to eavesdrop in the name of national security.

More recently, courts have rejected the government’s claims that it may, without a warrant, collect in bulk under the USA Patriot Act the telephone numbers that Americans call, or monitor an individual’s movements by using a device that intercepts the person’s mobile phone signals to obtain location information.

Robust enforcement of the Fourth Amendment’s privacy protection does not, however, tie the government’s hands in investigating violations of the law or fighting terrorism. The Fourth Amendment generally requires that when the government seeks to invade a person’s privacy, it must obtain a warrant that is issued by a neutral magistrate (like a judge), directed at particular items and places, and based on a good reason. In plain terms, what the Fourth Amendment prevents is an investigating officer deciding, on his own, to engage in a fishing expedition, based on a hunch. Fourth Amendment requirements thus interpose a neutral referee between law enforcement and individuals, to prevent officers from acting on prejudices or in a scattershot manner. If the government satisfies these requirements — which it very often does — then its search is constitutional. (The Fourth Amendment also has a handful of practical exceptions, such as one for emergency circumstances.)

What the requirements of the Fourth Amendment obstruct is not the use of surveillance, but its abuse. As the Supreme Court has explained, “Fourth Amendment freedoms cannot properly be guaranteed if domestic security surveillances may be conducted solely within the discretion of the Executive Branch” because “unreviewed executive discretion may yield too readily to pressures to obtain incriminating evidence and overlook potential invasions of privacy and protected speech.”

In our data-driven society, the next frontiers of privacy will be about our information. Can the government use your cell phone signal as a homing device to track your movements? Compile your prescription records into a database that it can search at will to learn about your medical conditions? Use drones equipped with sophisticated cameras to see inside your home?

All that stands in the way of such invasions is our willingness to stand up for our rights by demanding that our elected officials respect the Fourth Amendment and by advocating for the appointment of judges who will faithfully apply it when law enforcement does not.

So on this Constitution Day, among the provisions we should most fervently celebrate is the Fourth Amendment, which provides a check on executive authority to learn the most intimate details about our lives and thus safeguards that “most comprehensive of rights” — “the right to be let alone.”

• Scott Michelman is senior staff attorney at the American Civil Liberties Union of the Nation’s Capital. He teaches constitutional law at American University Washington College of Law and civil rights litigation at Harvard Law School.