According to The New York Times:
"(...) the judge, Shira A. Scheindlin, ruled that police officers have for years been systematically stopping innocent people in the street without any objective reason to suspect them of wrongdoing. Officers often frisked these people, usually young minority men, for weapons or searched their pockets for contraband, like drugs, before letting them go, according to the 195-page decision.
These stop-and-frisk episodes, which soared in number over the last decade as crime continued to decline, demonstrated a widespread disregard for the Fourth Amendment, which protects against unreasonable searches and seizures by the government, according to the ruling. It also found violations with the 14th Amendment.
To fix the constitutional violations, Judge Scheindlin of Federal District Court in Manhattan said she intended to designate an outside lawyer, Peter L. Zimroth, to monitor the Police Department’s compliance with the Constitution."
The practice of Stop and Frisk targeted minority youth (90% of those stopped were Black or Latino) and about 88% of all people stopped were innocent. According to the ACLU, only 0.2% of all stops led to finding a gun.
The decision by judge Scheindlin is extremely overdue, and you can read more about it here.