A childhood cryptography experiment nearly derailed a future security clearance when a misplaced glasses case led to an FBI investigation. In 1943, a 12-year-old Les Earnest and his friend Bob created a secret code based on letter frequencies from Fletcher Pratt's book on cryptography, carrying the code key everywhere.

Earnest's habit of wearing only swimming trunks outdoors meant his code key was hidden in his glasses case. When the case fell from a streetcar, a patriotic citizen found it, assumed it belonged to a Japanese spy, and turned it over to the FBI. The agency launched a six-week investigation, examining optometrist records across San Diego to trace the glasses.

The FBI eventually discovered the code belonged to a child, returned the glasses, but kept the code key "for our records." Years later, when applying for a Naval Electronics Lab security clearance, Earnest honestly disclosed the incident. The security officer tore up the form and warned him never to mention it again, stating he would ensure Earnest "never" received clearance if he did. Earnest followed this advice on all future security clearance applications.