Stop-and-frisk is unconstitutional as is unreasonable search and seizure often based on racial profiling. No warrants are issued and often the suspect has done nothing more then be born into a race considered likely to offend. Stop-and-frisk also provides easy outs for non-minorities to offend by being automatically deemed less likely to be stopped under stop-and-frisk.
The NYPD's stop and frisk policy was a complete violation of the Fourth Amendment, which specifically prohibits unreasonable searches and seizures. There was also no doubt that these searches were being done based on racial profiling, in violation of anti-discrimination laws. Being black and simply walking down the street has never been, and should never be, grounds for police harassment.