The shuddering growl of a Harley motorcycle is an intimidating thing. To most people it signifies the approach of bikers -- long-haired and tattooed, leather-clad, and tough.

But when children who have been the victims of abuse hear the approaching roar of a group called the Bikers Against Child Abuse (BACA), they know they've got back-up.

BACA, an international non-profit that uses a biker's tough image to make child abuse victims feel more secure, has a motto that says it all: 'No child deserves to live in fear.'

BACA members are usually asked to intervene by local law enforcement officials or even by a parent. According to the group's mission statement, members will do everything from attending a child's court hearings to actually staying with a victim if he/she is afraid.

“Our mission is to empower these children, allow them not to be afraid of the world, to stand up to the abuser and say you can’t do that me. I’ve got friends, I got backup; if you try to do that to me, you’re going to have go through us,” the Missouri chapter public relations officer, Mopar (the members use ride names for security purposes) told Columbia Magazine.

Bikers Against Child Abuse was founded in 1995 by a Native American child psychologist whose ride name is Chief, when he came across a young boy who had been subjected to extreme abuse and was too afraid to leave his house. He called the boy to reach out to him, but the only thing that seemed to interest the child was Chief's bike. Soon, some 20 bikers went to the boy's neighborhood and were able to draw him out of his house for the first time in weeks.

Chief's thesis was that a child who has been abused by an adult can benefit psychologically from the presence of even more intimidating adults that they know are on their side. "When we tell a child they don't have to be afraid, they believe us," Arizona biker Pipes told azcentral.com. "When we tell them we will be there for them, they believe us."

Membership in Bikers Against Child Abuse is a big commitment. If any of the kids are frightened, they only have to call and the bikers will ride over and stay outside all night, Pipes told azcentral.com.

Besides not using force, the bikers only have one rule. "I don't want to see any tears coming out of your eyes, and the child doesn't either," Pipes told a group of bikers during an interview with azcentral.com "Remember why we're here: to empower the child. If you can't handle it, keep your shades on." There's no crying in BACA.