Depends.
  One on one that might work.

  Many on one, no. It doesn't work.

  More important is being able to fight the battles you can fight,
  and then knowing when you need to get help.

  But then, what kind of help?

  Gang violence is sometimes the result of victim vigilante
  justice that grows into a force of its own. The victims become
  the bullies.

  The Meme is cute but oversimplifies a complicated issue and
  really, it's fucked up that we create systems like schools that
  shove future murderers with future nobel prize winners and then
  walk away when there's a problem.

  "Oh, you have a problem? yeah, fight it out. here's a kitchen
  knife. Make it count." and adult walks away.

  The adults are responsible for the systems we shove kids in for
  12 years. If we're not doing a good job monitoring things, then
  we've failed.

  Of course not every situation can be anticipated or handled, and
  by the time a kid DOES come to ask for help, they're often at a
  breaking point and desperate.

  One solution doesn't fit all situations but we can't absolve
  adult responsibility for at least some of the mess. How many
  suicides? Cutters? clinical depression? Are they social rejects
  who should be thrown away?

  Toughen up? Sure.

  But pay attention. Don't just say "get tough" and walk away.