Electromagnetically shielded portable storage devices are disclosed. One such device includes an electromagnetically shielded enclosure having an interior volume, the electromagnetically shielded enclosure including a plurality of shielded walls and sized to be manually carried by a person. The interior volume of the enclosure is isolated from high-frequency electromagnetic energy generated external to the enclosure. The device includes at least one storage device positioned within the interior volume, and at least one communicative connection extending from the at least one storage device to a communicative socket accessible external to the electromagnetically shielded enclosure. The at least one communicative connection is configured to allow access to the storage device by a computing system external to the electromagnetically shielded enclosure. The device also includes an electrical filter positioned at least partially within the electromagnetically shielded enclosure, and including a low-pass filter selected to prevent spurious or intentional conductive high-frequency electromagnetic energy from entering the interior volume via the communicative connection.