Someone, most likely an aging baby boomer with sticky fingers, has been lifting CDs from the music library at the Voice of America, which uses them for its radio shows. Looks like an inside job. The library is open only to employees. The M.O. is that the person goes into the stacks and takes the CD but leaves the plastic case.
The thefts were noticed recently when someone tried to check out a Judy Collins disc but found only an empty case. In fact, the entire Collins collection is gone. A check of other collections showed that Peter, Paul & Mary and Bob Dylan recordings were also missing.