@DarkMahesvara It wasn't a backdoor as that didn't allow anyone access to the devices, but that was clearly intentional so appel could claim that they were giving the used privacy, while allowing their spying friends to see the permanent MAC address.

Android is extremely proprietary even if some parts are released under licenses that qualify as "open source" ones and typically the peripheral software that handles Wi-Fi signalling is proprietary, but people know that gulag spies, so people to look at wireshark logs of bluetooth to see how, so I don't think gulag tried it.