Electronic vaporizers seem to have some fairly sophisticated electronics inside. Big tobacco can suck a lemon, but this teardown of a PM vaporizer is pretty interesting:
Apparently both the cartridge and the battery have a microprocessor (ATTINY84 in the battery stick) which communicate with each other over an encrypted channel to verify cartridge authenticity. It looks like an air flow sensor then increments a counter based on how long a drag one takes, and stores the result in EEPROM.
And if I'm reading the article correctly, cutting the LED leads may disable the whole system and allow cartridges to be reused.