Is the "knockout game" really new?

Chuck Williams, an associate professor at Drexel University, thinks not.

In case you're new to the "game," teenagers from across the country have reportedly attacked innocent strangers with a simple, disturbing goal: to knock them out with a single punch. The trend has been spotted everywhere from Chicago to Hoboken, N.J.

Williams studies youth violence, but he is also an expert on the topic for another reason: He grew up in North Philly in the 1980s, when teens also assaulted defenseless strangers for apparently no reason, he said. They just had a different name for it.

"Let's find somebody that we wanna 'roll on,'" Williams recalled. "That was back in the day."

In one incident, Williams said a boy who lived outside his neighborhood randomly struck another male.

"He hit someone that I know had not done anything to him, and wasn't really a target because they were beefing or anything like that. It was a random thing," he said. "They laughed and they walked away. So it's not something that's new."

Williams said the only difference between random assaults that took place decades ago and the "knockout game" is that people are now spreading videos of the attacks on social media.

"Now there's almost like this whole market for it, which creates another problem," he said. "People now have an appetite for this kind of public display of inappropriate aggression. And that, to me, is dangerous."

Philadelphia police did not respond to questions about the "knockout game." SEPTA spokeswoman Jerri Williams said officials have found no evidence of the trend taking place here.