I think based on how Hashstaker is marketed it's not "crypto" and does not depend on computational resources any more than a bank account or a bond. It might be marketed as something confusingly novel, but the fact is that you put money in and take more money out, and with GAW starting to "sell" PayCoin on Monday it looks like a lot of people will be putting USD in and expecting to get USD out. Also the TOS risk disclosures posted a few posts back sound very much like investment risk disclosures.
Consider an analogy. I say buy a "Fundlet" for $100. The Fundlet will come in flavors: Vanguard 500, Fidelity Contra, etc. I will pay you daily based on the profits of those funds. Would anyone seriously argue that the Fundlet isn't a security? How can a Hashlet be any different??
You can't just black box it or any activity that ever involves resources and profit is a "security". It matters that it not just depends on computational resources but actually consists of computational resources. That's what a non-Zen solo hashlet is.
Now, you might not believe that, in which case there could be some kind of violation. But based on the evidence out there, non-Zen solo hashlets do not rely on the efforts of people besides occasional incidental maintenance.
Other than ZenPool and misrepresenting the risk involved in PayCoin price support, I don't see a lot here. ZenPool could kind of be a big deal, though. Even with ZenPool, though, there's a chance it could be some kind of subleasing arrangement, although it's very difficult to construct scenarios where there's not some kind of securitization.