I think the problem here, that will catch other online providers, is that snapchat's success is still based on the flawed presumption that it's actually private

I think the problem here, that will catch other online providers, is that snapchat's success is still based on the flawed presumption that it's actually private (by any of your definitions). Hopefully the realization that these services aren't as private as advertized will have a ripple effect in the "younger markets", but I doubt it.