They really do! Bystanders have the opportunity to look like leaders and change opinions. A bystander is a bullied child's best friend.
Encourage your child to either speak up in the crowd when a bully is bullying a victim. It does not have to be a reprimand in nature. Bystanders can use humor, they can distract or they can pull the bully off to the side and let them know "it is not cool and they should stop."
Encourage your child and their friends to make a pact to defend other children, not just their friends, but everyone. Bullies will back down if someone defends a bullied child. It simply takes good parents to remind children that this is part of being a day-to-day human and it takes a little courage.
Bystanders are leaders, tell your child everyday.
For more information, see solutionsforbullying.com