[Assuming ATC request me to turn it off]
The only reference I can find to this rather unlikely scenario is:
"Requests to stop ADS-B transmissions shall only be made in the event of known or suspected airborne or ground system faults. In aircraft without pilot access to the ADS-B avionics, the pilot shall deactivate the ADS-B transponder in accordance with procedures approved by the aircraft operator. If this is not possible, advise ATC immediately."
http://legacy.icao.int/icao/en/ro/ap..._2003/wp04.pdf
Probably not worth losing any sleep over.