It would be interesting to see a Wallet that warns you about freq, in the are that can READ your card in you pocket.
Place it in the wallet, and when the strngth, and freq happen, IT VIBES AND SCREAMS.
This is a comment on people making, Wallets and devices that Scan your Data off your cards and including other credentials. A small device that will intercept Those using scanners at close range.
The idea is kinda simple as any Fairly strong freq at close range, should be easy to Identify.