Privacy is on trial in the United States. Legal activist Larry Klayman asked US District Judge Richard J. Leon to require the NSA to stop collecting phone data and immediately delete the data it already has. His argument was that US citizens have a right to privacy and this is a violation of the Fourth Amendment of the Constitution protecting citizens from illegal search and seizure. Monday's ruling that this practice is unconstitutional has privacy activists cheering in the streets, but it will not be a lasting victory.
In the United States, there is not a single privacy law on the books. (You can argue that HIPAA is a privacy law, but nuances exist that can lessen its impact.) What is protected has come from judgments based on the application of the Fourth Amendment regarding search and seizure. US citizens were given "privileges,” thanks to Richard Nixon, which say we have an expectation of privacy when using a phone, which basically means that the government has to get a warrant for a wiretap. (It’s worth noting that in the UK, they don’t get that privilege.)