(CNN) -- A recent cell phone video of two Philadelphia police officers during a stop-and-frisk has caught the attention of online viewers and the American Civil Liberties Union -- and the police department itself, which says it its investigating.
The over-16-minute long YouTube video dated September 27 depicts two male Philadelphia police officers confronting two unidentified pedestrians, one of whom recorded the incident on his cell phone.
It is unclear who posted the video online, but police have not challenged its authenticity.
Despite the lengthy and often caustic questioning of the men, they are allowed to walk away by the officers.
The video begins with a police vehicle slowing down as one officer is heard saying, "Yo, my man," before the vehicle comes to a complete stop. "How you doing sir?" one of the pedestrians replies, as the officer in the passenger seat of the vehicle opens his car door and steps out on to the street.
After inquiring whether the pedestrians have identification or live in the area, the second officer exits the vehicle and joins them on the sidewalk.
One pedestrian asks, "What seems to be the problem?" as the other says he is on his way to work.
The officers then begin questioning why the pedestrians said "hi" to a third, unseen individual on the street before the video begins.
"You don't say 'hi' to strangers," one officer remarks. After one pedestrian disagrees with this, both officers immediately restrain his arms and push him up against the police vehicle.
The pedestrian recording the confrontation on his cell phone attempts to walk away from the scene but is stopped by an officer who tells him to put his phone away because he is "under investigation." The phone is placed down on the ground facing the sky and continues to record audio.
"Investigation of what? I was walking," the pedestrian argues, prompting the officer to reply, "That's not what I saw," later threatening, "If you keep running your mouth I'll split your wig open."
After examining the pedestrian's ID, the officer interrogates him on his legal past. The pedestrian admits to being arrested once for fighting. "That's it?" the officer responds sounding surprised.
The officer begins asking questions about the pedestrian's cell phone and whether or not he is being recorded, taking the phone and turning it around to face the ground, the audio continues to record but the image is constricted.
"Are you accusing me of robbing somebody?" the pedestrian asks.
"I didn't accuse you of anything can you hear?," the officer shouts, "We could've got a call, that somebody wearing the clothes that you're wearing just robbed somebody, that's why we stopped you. Is that wrong of us?"
The officer then yells to the other pedestrian who was last seen being pushed up against the police car a few feet away, "Why don't you shut up?"
"Everybody thinks they're a (expletive) lawyer and they don't know jack (expletive)," the officer continues to yell.
After next accusing the two pedestrians of jaywalking, the officers can be heard returning the pedestrians' belongings and allowing them to leave. The video ends after this.
The video is titled "Police unlawful harassment and racial profiling," but the race of the men who were stopped was not specified in the video.
According to Mary Catherine Roper, a senior staff attorney for the ACLU in Pennsylvania, there is no investigative purpose for humiliation and verbal abuse in such a situation, even if this particular stop was for an adequate reason.
"You do not call people trash, you do not call them a burden on society, you don't threaten to split their wig. It went way beyond what a stop is supposed to be," Roper said, making references to remarks by the officers during the stop.
Philadelphia Police Department's Internal Affairs is conducting an investigation into the officers' actions as seen in the video, according to public affairs spokesman Lt. John Stanford.
"The Department takes this very serious and we don't tolerate unprofessional or distasteful behavior by any member of this department," Stanford said in a statement this week.
Police will not release the two men's identities or the names of the two male officers who stopped them, according to public affairs spokesperson Officer Jillian Russell. While it's unclear whether the pedestrian who recorded the video is also the person posting it online, that's not significant to the investigation, Russell said.
This is not the first time Philadelphia police practices have been under scrutiny. In 2010, the ACLU filed a lawsuit against the Philadelphia Police Department for stopping pedestrians without reasonable suspicion. Rather than litigating, the city chose to negotiate and in June 2011 it consented to a "mirror monitoring program," in which prosecutors reviews police-stop material from a random, selection of records collected quarterly, Roper said.
Since reviewing the stop material, Roper found that 45% of pedestrian stops do not have a legally adequate reason. Roper said examples of an inadequate reason are "loitering" or "acting suspiciously."
"My favorite one was a man who was carrying a chair," she said. "(The police) assumed he had stolen it."
While Roper has seen a decrease in the number of stops since she started reviewing the city's police stop material, that doesn't indicate whether the stops are being conducted lawfully, she said. In fact, it might mean for the department to retrain officers on not just when it's appropriate to stop pedestrians but also how to appropriately conduct a stop, which the ACLU may decide to request, she said.
Roper said she strongly believes police officers want to do the right job when the department's expectations are made clear to them, but an "ingrained police practice" will not be a quick fix.
"An attitude is far more difficult to change," she said.