It's something that more than half of 12- to 20-year-olds participate in every year -- underage drinking.
Fifty-three percent of all people age 12 to 20 have engaged in underage drinking at some point in their lives, according to a study by the United States Department of Health and Human Services. The 2008 study also found that 650,000 of the underage drinkers were provided alcohol by their parents.
But what about the adults who say no to teens?
"What Would You Do?" wondered: If a minor approached you in front of a store to buy them alcohol, how would you respond? Would you say no? Would you alert the police? The store owner? Or would you say yes?
"What Would You Do?" hired three male actors, all over the age of 21, to play 18-year-olds asking adults if they would be willing to buy them beer. Our location: Station Liquors in Rutherford, N.J., rigged with our hidden cameras to see how people would respond to our actors' pleas.
'Excuse Me? I Was Wondering if You Could Help Me and My Friends'
When we started the day, we positioned our three young actors on the sidewalk in front of the liquor store.
The very first person the "teens" approached stopped and listened to their request for beer.
"How old are you?" she asked.
After the actor responded that he was 18, the woman asked what he wanted -- and she seemed amenable to his request, with a condition.
She told the group that they needed to be out of eyesight of the store owner.
"Are you parked in the parking lot? 'Cause you can't hang out here and I give that to you. I'm not going to do it right in front of this store. He'll have me arrested," she said.
After the money changed hands, she headed straight to the counter, only to meet us.
"Well, I told them I didn't want to do it because it was illegal. But, when I was 18 it was legal," she told "What Would You Do?"
"But, I'm doing the wrong thing," she added. "I have kids and if that happened I would be angry."
In that case, the woman's sympathy for our actors seemed to have been fueled by history. In 1984, the federal government successfully pressured states to raise the drinking age to 21. Before that, in more than two dozen states -- including New Jersey, where our scenario was based -- people between the ages of 18 and 20 were allowed to drink legally, meaning that some of the people who passed by our actors were drinking legally by the time they were 18.
Would that fact continue to help our "minors"?
'I'm Calling the Cops Right Now. You Abused the Law'
As the guys headed back to the street they approached a man walking by the store and were met with an immediate "no."
But, just a few seconds later, as a woman was about to head into the store, our actor called out, "Excuse me? I was wondering if you could do me and my friends a favor."
"You want me to by some beer?" she asked.
Our actors told the woman what kind of beer they wanted and gave her $20. Before long, she was in the store attempting to buy our "teens" the beer.
When we met up with her she said, "I didn't know they were underage."
At first, the success rate of our actors was surprising: Two out of the first three people they approached agreed to buy them beer.
But soon, a string of rejections followed.
As our actors were met with many no's, one woman walked into the liquor store to alert to the owner.
"Uh, heads up. There's three kids out there that want people to buy them beer" she said to the store owner.
And then our actors were met with the most passionate response of the day.
"Excuse me sir, I was wondering if you could do me a huge favor," said our actor.
The local restaurateur was wary from the start.
"You're not asking me for money, are you?" he asked.
"No, I'm not asking for money. I was wondering if you could go in and just get us a 12-pack," the actor said.
The situation quickly turned into every teenager's nightmare as the man began to grill our actors like an interrogator.
"You have a mother and father?" he asked. "Why don't you ask your mother and father? How old are you? What is the law to drink?"
The man demanded the actor's phone number, then threatened to call the police.
"You abused the law," he said.
When we met the local business owner later, he told us that when he saw our actors he was reminded of his own son. We told him that during the course of the day there were some people who had no problem helping out our teens.
His response, "Shame. You don't have to get drunk to have a good time… I don't need alcohol…I need a good friend.""
Overall, the "teens" approached nearly 25 people. Five of them took their money and agreed to buy them beer.
But what would happen when we switched the three male actors with three female ones?
Watch the scenario unfold on "What Would You Do?" Friday at 9 p.m. ET.