If you plan to visit a college campus this month, don't be surprised if you see signs and placards encouraging you to "Restore the Fourth." Restore the Fourth is not about an athletic event or a holiday; it is about human freedom. The reference to "the Fourth" is to the Fourth Amendment, and it is badly in need of restoration.

In the dark days following 9/11, Congress enacted the Patriot Act. The Patriot Act has many flaws, including its prohibition of certain truthful public speech, but its most pernicious assault is on the constitutional right to privacy.

One of its sections permits federal agents to write their own search warrants and serve them on persons and entities who by law are the custodians of records about others, such as physicians, lawyers, bankers, telecoms, public utilities, and computers servers. The same section of the act has been used perversely by the NSA and the secret FISA court to authorize the bulk collection of data. Bulk collection of data—the indiscriminate governmental acquisition of the contents of emails, text messages, telephone calls, bank statements, and credit card bills—is what the NSA seeks when it acquires all data in a specific area code or zip code or from a named provider, like Verizon, AT&T, and Google.

What's wrong with bulk collection? The warrant issued by the FISA court that authorizes bulk collection is known as a general warrant. A general warrant does not name a person or place, but authorizes the bearer to search wherever he wishes and seize whatever he finds. General warrants were a tool of colonial repression used by the king prior to the American Revolution. They were issued by secret courts in London. They were so loathed by the Framers that they are expressly forbidden by the Fourth Amendment.

The Fourth Amendment requires evidence—called probable cause—about a particular person, place, or event to be presented to a judge and requires the judge to decide whether it is more likely than not that the government will find what it is looking for. The wording of the amendment could not be more precise, and in a Constitution known for vague language, this precision is instructive: All warrants must "particularly descr(ibe) the place to be searched, and the persons or things to be seized." The Fourth Amendment protects all persons' bodies, houses, papers, and effects.

Yet the Patriot Act purports to avoid these requirements by permitting secret FISA court judges to authorize NSA agents to execute general warrants; thus, without probable cause and without describing the place to be searched or the person or thing to be seized.

The purpose of the Fourth Amendment is to prohibit government fishing expeditions, common to totalitarian countries. The theory of the Fourth Amendment is that a restrained government—restrained by an instrument the government cannot change, like the Constitution—is essential if people are to be free. The natural right protected by the Fourth Amendment is the right to be left alone.

Enter Restore the Fourth.

Restore the Fourth is a movement gaining steam now because the section of the Patriot Act that is so constitutionally offensive expires on May 31. President Obama wants it extended so his spies can continue their bulk collection of data. The Republican leadership in the Senate agrees with the president and accepts the myth that less freedom equals more security. The Republican leadership in the House has proposed a Band-Aid that would require the telecoms and computer service providers to sit on bulk data until the feds come calling, but to surrender it without the judicial finding of probable cause or specificity.

The Patriot Act should be repealed because it violates the Constitution and it doesn't keep us safe. It renders us less safe and less free. The indiscriminate unconstitutional bulk collection of data is far too much raw material even for the 60,000 NSA agents and contractors to navigate. We saw that as recently as last weekend, when two jihadists known to the FBI and who had used email and cellphones attacked a free speech symposium outside of Dallas and were stopped at the last minute by courageous local police who saw their guns—not by federal spies' warnings.

When longtime NSA Director Gen. Keith Alexander was asked under oath how many plots the NSA has stopped in 10 years, he stated 53. The next day, he modified his testimony to three, but declined to elaborate. Edward Snowden, whose revelations about NSA spying have never been refuted, says that no plots have been stopped because the NSA looks at everyone, rather than targeting the bad guys, as the probable cause requirement—if complied with—would induce it to do.

Americans are largely free because of the rule of law. The rule of law means a supreme law of the land to which even the government is subject, just as are all persons. Without the rule of law, we are subject to the rule of whoever runs the government, and our rights become licenses to be granted or denied by whoever runs the government. In that world, who or what would restrain the government? An unrestrained government is what we fought the American Revolution against.

That's why we must Restore the Fourth.