CIA Spies On New Yorkers

Peaceful protests are allowed and protected by the 1st amendment to the constitution. Why is the federal government's overseas spy agency, the CIA, spying on Americans in New York City?

CBS news has the story on CIA spying in New York City:

Three months ago, one of the CIA's most experienced clandestine operatives started work inside the New York Police Department. His title is special assistant to the deputy commissioner of intelligence. On that much, everyone agrees.
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The CIA is prohibited from spying domestically, and its unusual partnership with the NYPD has troubled top lawmakers and prompted an internal investigation.
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All of this has troubled lawmakers, including Sen. Dianne Feinstein, D-Calif., the chairwoman of the Senate Intelligence Committee, who has said the CIA has "no business or authority in domestic spying, or in advising the NYPD how to conduct local surveillance."