But how to get the attention of young people like Phillip Barren, a 16-year-old sophomore at the Multi-Cultural Academy Charter School?
"No one wants to look at a piece of paper or listen to an adult just standing in front of us," he said.
So what if you let Barren and his friends deliver the message?
The charter school is at Broad and Butler Streets. Students wear uniforms and prep for college. Parents choose it for its structure and strictness. But its no-cellphone rule couldn't protect the students from electronic bullying this year.
In October, someone made a fake Facebook page for the school and used the space to talk trash about a couple dozen students - mostly girls. This year, the parents of a girl told police their daughter felt threatened by something another girl had posted, Principal James Higgins said.
"These kids don't understand when you post something on Facebook, it's out there. You can't take it back. You're fully responsible for your words. That hasn't sunk in."
So Lauren Smith's drama class had real material to mine. For a month, a dozen of her students have been developing a script from personal experience.
I sat for an hour with the class one day last week, listening to them talk about the combustion of technology and sex.
One of them - Barren, again - knew of someone victimized by sexting. A guy had taken a picture of his girlfriend topless. And when the couple broke up, the guy sent the picture to six of his friends. No telling where it went from there.
The PSA they wrote takes the form of a call and response. Sophomore Brianna Torrence started things off in rehearsal.
"If you love me," she began.
"You wouldn't tell me who to be friends with," a student replied.
"You wouldn't be jealous all the time."
"You wouldn't call me stupid."
On Monday, the class is to start taping. Mike Gallagher, an IT worker at St. Joseph's University, will direct. He's the 20-something I wrote about last year who decided to walk across America. Kefalas found a young Philadelphia actor to star.
The class created a simple and cheap plan for distribution. All but one of the students I talked to has a Facebook account. They'll just post the video on their walls and see whether it goes viral.
To beat the Internet, Kefalas said, you have to join the Internet.
"Adults have made a huge tactical mistake saying the Web is scary," Kefalas said. "There are a lot of ways for parents and teachers and other people who are important in young lives to join the conversation on the Web. Kids can infect the culture." She means that in the best way.
"If you loved me . . ."
"You wouldn't hurt me."
"You wouldn't hit me."
"You wouldn't humiliate me."
"You wouldn't scream at me."
"You wouldn't make a fake Facebook page just to make fun of me."
"You wouldn't tell your friends to follow me home."
"You wouldn't make me do things I don't want to do."
"You wouldn't say I can never leave you."
Contact Daniel Rubin at 215-854-5917 or firstname.lastname@example.org.