[georgeam]

I'm a strong believer in solving problems at the single point of failure. If you solve it at the Twitter level, what about any other internet/cloud based service that is designed just like Twitter? It would still be a problem. If you solve it at the phone company level, all the companies that operate like Twitter are protected.

Even better still, solve it at both levels, but definitely don't let phone companies off the hook.

[rmtech]

Yeah, I think it should be solved in both places TBH. Defense in depth.

But it won't happen because people are dumb and don't care about the issue until the exact moment it bites. This basically applies to every security problem: everything is perpetually broken and therefore nefarious actors can always find a way to achieve their goals. Most people's best defence is to not have any enemies.