I want to know the answer to the following question:
What is the controversial N.S.A. program used in the U.S.?
All the background I'm provided with is that "In the U.S., a controversial National Security Agency program known as PRISM provides for broad monitoring of Internet users traffic and has raised concerns about potential violation of the privacy protections in the Fourth Amendment to the United States Constitution.". Is that enough to answer the question?
Answer: yes