Ironically, using an old tech incandescent lamp in place of the LED would make the detection impossible, the reason being that incandescent lamps are way slower to turn on and off than LEDs, therefore it would work as a low pass filter just like putting a capacitor in parallel to the LED, which makes a RC filter paired with the series resistor preceding it.
Of course one could still use LEDs of which they have gained control for exfiltrating information, whether LEDs have a capacitor in parallel or not. If there is a capacitor and the LED can't be turned on and off effectively at say more than 5Hz, one could just use 1Hz pulses and, given enough time, transmit the information anyway.
Of course one could still use LEDs of which they have gained control for exfiltrating information, whether LEDs have a capacitor in parallel or not. If there is a capacitor and the LED can't be turned on and off effectively at say more than 5Hz, one could just use 1Hz pulses and, given enough time, transmit the information anyway.