In the criminal community, the term "songbird" means snitch, rat-fink, or singing canary. It is a derogatory means of marking people who inform on unlawful offenders to the law enforcement authority.
Many informants accept monetary recompense; many do not. They simply own such a strong sense of right versus wrong that they willingly aid the law enforcement community by imparting their information to the proper authorities.
They risk extreme hardship in many incidences. However, these songbirds consider a clear conscience well worth the risk.
This is a truthful account of two such songbirds.