I reserve judgment as to whether it was Twitter's fault or Smyte's fault, but at the very least, it was Smyte's fault for selling to Twitter without getting any

I reserve judgment as to whether it was Twitter's fault or Smyte's fault, but at the very least, it was Smyte's fault for selling to Twitter without getting any guarantees for their existing customers. At the worst, they shut down the service like this themselves. Again, if it turns out that Twitter lied to them about how the service would be wound down, I'm sure that will come out in due time. If I were one of the founders (and I know at least one of them has been often on HN), then I'd be on this thread making some explanations right now. Finally, the name of the founders isn't some kind of secret. This is public information. The founders have been featured in many media pieces. They sold their company to a public company.