The USA PATRIOT Act is a landmark Act of the United States Congress, signed into law by President George W. Bush. The formal name of the statute is the Uniting and Strengthening America by Providing A
A warrant canary, posted in a Craftsbury, Vermont library in 2005: "The FBI has not been here (watch very closely for removal of this sign)". Announcing the receipt of a national security letter would violate the associated gag order, while removing the sign would not.