The NYPD calls it targeted and precision policing, the arrest of large numbers of gang members at one time. But some are questioning the practice. NY1's Dean Meminger filed the following report.

Thousands of people who police say are violent gang members have been arrested in the last few years in massive takedowns.

"When you arrested 120 young people from one neighborhood and you only alleged that only two or three were directly involved in violent activity, just how precise is that?" said Alex Vitale of the Policing and Social Justice Project and Brooklyn College.

Often, the gangs are hit with a conspiracy case, resulting in every member being charged with participating in the violence. Activists view that as unjust.

Last month, 19 alleged members of a gang based at the Boston Secor Houses were busted. Last year, 120 people from the Eastchester and Edenwald Houses were federally indicted.   

"They are coming into housing projects like they are fight ISIS," said Hawk Newsome of Black Lives Matter NY.

Now, public defenders, professors and community activists are calling on the NYPD's inspector general to investigate police department tactics and surveillance of alleged gang members. 

"What is the status of gang databases that have been the subject of litigation in certain parts of the country?" Vitale said.

The group says an NYPD form shows people can be classified as being part of a gang for any of several reasons, such as being seen at known gang locations, wearing certain colors or tattoos, or using gang hand signs.  

"We have a very high standard, a threshold before we put anyone in a gang database," said NYPD Chief of Detectives Robert Boyce.

The NYPD says it does remove names from the gang database when appropriate. But those asking for an independent investigation find that hard to believe.

"We had about 100 gang takedowns in 2016. We had about 1,000 were people arrested. All of them involved in violence and crime," said Police Commissioner James O'Neill. "So we are targeting the right people."

"A lot of this young people are 18-, 19-year-old kids from the hood who don't have the money to hire a high-powered lawyer like John Gotti would," said Josmar Trujillo, a community activist.

The NYPD inspector general says he's aware of the request that he investigate. He wouldn't say whether he will.