a device for preventing unwanted electromagnetic inquiry of an electronic card storing information thereon by the transmission of a rogue interrogating signal from an rfid skimmer proximate the electronic card . the device comprises a first and a second conductive material layer each operating to detune an antenna associated with the electronic card or to detune front end resonant circuits associated with the electronic card , and one or more third material layers having a greater thickness than the first and second layers and disposed between the first and second layers , the one or more third material layers providing electromagnetic shielding against radio frequency signals emitted from the electronic card .