What are the limitations of a Faraday bag?¶

A Faraday bag can reduce wireless communication, but it has practical and evidential limitations.

Evidential caution: that once the device is inside, no further change can occur. The device remains powered and may continue running applications, writing logs, locking, draining its battery or acting on commands already received.

What this means¶

Shielding may be incomplete if the bag is damaged, worn, folded badly or not fully sealed.

Different frequencies and device types may behave differently. A bag that works well for one device may be less effective for another.

Any cable entering the bag may create a communication path and weaken the isolation.

The device may repeatedly search for a network, which can increase battery use. If power is lost, volatile evidence and live access may disappear.

The screen may no longer be visible once the device is sealed, so the original state must be recorded first.

Removing the device to check it defeats the purpose and may allow immediate reconnection, synchronisation or delivery of pending commands.

Its effectiveness may also reduce over time through wear, damaged seams or repeated opening and closing.

Where prolonged isolation is required, specialist advice may be needed on power management, controlled charging and later examination.

What to check or do next¶

• Record the bag identity, condition, sealing method, time of placement and any later removal.
• Do not describe the device as fully isolated unless that has actually been established.

Evidential limits¶

A Faraday bag also does not address wired connections, internal storage changes or actions already scheduled on the device.