A federal judge blasted the NYPD's use of stop-and-frisk as unconstitutional on Monday and appointed a federal monitor to oversee the program - a move Mayor Bloomberg warned could have deadly consequences.

"There is just no question that stop-question-frisk has saved countless lives. And we know that most of the lives saved, based on the statistics, have been black and Hispanic young men," a combative Bloomberg told reporters at City Hall, where he denounced the finding by Judge Shira Scheindlin that cops had been making "unconstitutional stops and conducting unconstitutional frisks" based on race.