I'm curious as to how this will interact with things like state-mandated do not call registries. Currently I can register my phone number such that businesses a

I'm curious as to how this will interact with things like state-mandated do not call registries. Currently I can register my phone number such that businesses are not permitted to cold-call me; if this were, say, Skype or Hangouts, then I would have to give ScamCo plc my account name and accept a request from them (or vice-versa), but since services like Whatsapp don't have any concept of mutual consent before contact, I don't get to be asked whether I'd like to hear from them. I expect it also won't be too long before marketing execs start clamouring to be allowed to use "rich text" and images, and we'll all get to start receiving dodgy Javascript through Whatsapp. Ho hum.