ON ABC NEWS' "PRIMETIME: WHAT WOULD YOU DO?," FRIDAY, MARCH 11

What will happen when a gym member blatantly disregards proper gym etiquette? Will anyone stop "mean girls" from bullying online? Some cases seem to cry out for action - while others seem to present a choice. What would YOU do? Using hidden cameras, "What Would You Do?" establishes everyday scenarios and then captures people's reactions. Whether people are compelled to act or mind their own business, John Qui�ones reports on their split-second and often surprising decision-making process. "Primetime: What Would You Do?" airs FRIDAY, MARCH 11 (9:00-10:00 p.m., ET) on ABC.

This week's scenarios include:

· Work-out From Hell: Health clubs and fitness centers around the country are more popular than ever, but they're also a hotbed for some bad behavior and lack of respect for others. "WWYD's" hidden cameras looks at etiquette at the gym � will anyone speak up when a man monopolizes the equipment, or refuses to clean up his weights, or chats on his cell phone while others wait their turn? And what will happen when the "WWYD" "gym member" enters a gym class late, talks and laughs and even take on the instructor during the routine?

Video preview: http://abcnews.go.com/WhatWouldYouDo/video/gym-class-antiheroes-13094714

· Flirting with Danger: A couple sit at a bar having dinner together. The wife is very into the husband, but the husband is paying very little attention to her. When she excuses herself to go to the bathroom, the husband aggressively hits on a single woman seating nearby, asking if she would like to go out sometime. Will bystanders blow the husband's cover when his wife comes back from the bathroom?

· Online Bullying: The anonymity of the internet allows individuals to bully and tease relentlessly and often with little consequence. So "WWYD" set up a scenario to see if any patrons of a coffee shop will intervene when they overhear "mean girls" harassing a fellow classmate over the internet with degrading comments and unflattering pictures.

"Primetime: What Would You Do?" has won awards from the Chicago International Television Festival, and the Avon Foundation's 2006 Voice of Change award for exposing "injustice and wrongdoing against women and bringing the message of domestic violence to the mainstream." The Columbia Journalism Review has called the program "a Candid Camera of Ethics."

David Sloan is executive producer and Danielle Baum Rossen is the senior broadcast producer of "What Would You Do?"