For nearly a century, the Boy Scouts of America has relied on a confidential blacklist known as the perversion files" as a crucial line of defense against sexual predators. That barrier, however, has been breached repeatedly. A Los Angeles Times review of more than 1,200 files dating from 1970 to 1991 found more than 125 cases across the country in which men allegedly continued to molest Scouts after the organization was first presented with detailed allegations of abusive behavior. Predators slipped back into the program by falsifying personal information or skirting the registration process. Others were able to jump from troop to troop around the country thanks to clerical errors, computer glitches or the Scouts' failure to check the blacklist. In some cases, officials failed to document reports of abuse in the first place, letting offenders stay in the organization until new allegations surfaced. In others, officials documented abuse but merely suspended the accused leader or allowed him to continue working with boys while on "probation." In at least 50 cases, the Boy Scouts expelled suspected abusers, only to discover later that they had reentered the program and were accused of molesting again.