PHILADELPHIA (CBS) — Philadelphia’s police commissioner delivered a stern warning to his officers after a lawyer reviewed how police officers behaved on social media. Hundreds of Philadelphia police officers, some ranking sergeants and lieutenants, have been outed for alleged racist and violent posts across social media.

There are thousands of Facebook comments and shared posts now compiled in a database called the Plain View Project.

The posts show officers wanting to ram people with Obama bumper stickers and others calling those in the Black Lives Matter movement “racist pieces of [expletive].”

“These public postings by active duty police officers are appalling. Blatantly violent and racist comments like this indicate a level of impunity and indifference to public accountability,” said Councilmember Helen Gym. “This isn’t just about correcting individual acts of misconduct—it is about demanding the accountability that our communities deserve.”

There’s also sexism, bigotry, threats of violence and calls for the executions of protesters which were all allegedly written by sworn officers.

“In an era where you’re striving your best to cultivate relationships with communities across the city, things like this don’t help,” Philadelphia Police Commissioner Richard Ross said.

In his remarks to police academy graduates on Monday, the commissioner alluded to the controversy eclipsing some 300 members of his force.

“Try your damnedest not to do anything to embarrass that, not to do anything that would upset that brand, because it doesn’t take but one to do it,” Ross said. “Please uphold yourself in the most utmost professional way that you can.”

Philadelphia is not alone. Officers in other major cities are caught in the crosshairs of troubling social media behavior charted in the database.

The ACLU said the magnitude of officers involved is profoundly disturbing.

“The department needs to understand this is a culture problem and they need to find a way to address the culture problem,” said Pennsylvania ACLU deputy legal director Mary Catherine Roper.

Fraternal Order of Police President John McNesby said in a statement, “We strongly condemn violence and racism in any form. The overwhelming majority of our 7-thousand officers regularly act with integrity and professionalism. We simply ask, who is watching or policing those that target law enforcement with violence, racism and unacceptable behavior? We stand with our officers who serve in our neighborhoods every day and keep us safe.”