As detailed in the book about post-9/11 Muslim surveillance, Enemies Within by Matt Apuzzo and Adam Goldman, the NYPD has long investigated specific communities: Italians and anarchists in the beginning of the 20th century; Germans and Japanese during World War II; Communists later on. Then in 1971, a lawsuit was filed against the NYPD after Vietnam War protesters and the Black Panthers alleged that police were photographing activists, posing as journalists and infiltrating civil rights organizations. That suit was known as the Handschu case, after lawyer and activist Barbara Handschu, the lead plaintiff.
WNYC, “Muslim New Yorkers Now Have Someone Watching the Cops Who Watch Them”
