With sites like Facebook and YouTube, and a cellphone in nearly everyone's pocket, we're seeing more cases of people witnessing violent incidents without intervening or summoning authorities.

Screen shot of fight in Camden in which two teen girls were attacked (6 ABC)

In Camden, bystanders used their phones to record an attack on two teen girls last week, instead of calling for help. In June, a Salem woman was recorded as she punched and kicked her co-worker, right in front of the victim's 2-year-old son. Both incidents occurred in broad daylight.

"People are attracted to that kind of thing," said Nick Irons, professor of criminal justice at the County College of Morris. "Why do people watch when a car wreck happens?"

Irons said some people may not want to step in because they fear getting hurt themselves.

"If somebody's swinging fists, you could get slugged with one too," he said. "People will take a back seat to that, and I, quite frankly, don't blame them."

There is no law in New Jersey against doing nothing.

For those who witness a violent act and are unwilling to intercede, Irons suggests they "yell as loudly as they can" to get the attention of the combatants, law enforcement, and perhaps someone else who is willing to take the risk and help.