Aside from 9/11 are there any historical events where personal privacy has been taken away to increase national security?
The right to privacy per se had never been enumerated until the Supreme Court's ruling in Griswold vs. Connecticut (1965.)
The foregoing cases suggest that specific guarantees in the Bill of Rights have penumbras, formed by emanations from those guarantees that help give them life and substance. Various guarantees create zones of privacy. The right of association contained in the penumbra of the First Amendment is one, as we have seen. . . .Fourth Amendment explicitly affirms the "right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures. . . .The Ninth Amendment provides: "The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people.
There were, however, instances in which the government took actions in he name of national security which obviously violated the constitutional rights of U.S. citizens.
The first such instance was the Sedition Act of 1798, one of the Alien and Sedition Acts, which prohibited publication of false, unfriendly or malicious material criticizing the government. Later examples, during World War I, included the Sedition Act of 1918 which prohibited the publication of material
disloyal, profane, scurrilous, or abusive about the American Government, Constitution, Army, or Navy
It is highly doubtful that these statutes would be upheld given the present attitude of the high court toward protection of citizen's rights. However at the time, national security was deemed more important than the rights of individual citizens.
The most obvious historical event in which this happened in US History was the Civil War. In those times, the government did not have the ability to do wiretaps or anything like that, but it did take away rights in an attempt to maintain national security.
In the Civil War, President Lincoln did a number of things that took rights away from the people. For example, he suspended the right of habeas corpus, meaning that people could be arrested and held indefinitely without being charged with a crime. As another example, he ejected Clement Vallandingham (a "Copperhead" Democrat) from the country because of his anti-war beliefs.
In these ways, the government reduced privacy and personal rights in an attempt to ensure national security.
Lincoln suspended Habeas Corpus in the interest of Northern security.
He even had the Legislature of Maryland arrested to stop them from seceding from the Union, that is, repealing the ratification of the Constitution.
FDR interred Japanese citizens when Pearl Harbor was attacked.
I am safe to say, I suppose, during the War of 1812 when the British occupied D.C. and burned the the White House, certain "round ups" took place to detain wiley individuals?