Regulate it yourself, in the sense that you spend time getting to know the people behind the project you are planning to finance, scrutinizing their plans, and generally doing the job that you trust the government with in the case of regulated securities.
The problem with that is it's frequently impossible. Case in point, I know a long-term, savvy investor (in the real world, not in Bitcoin) who got taken for $250k recently by a new startup that was probably just a shell. They had a great business model, great product, and both an extremely personable CEO and CFO who each took time to get to know their investors, and were always available to answer the phone. The only problem that stood out - to me - was that they were
too available to answer the phone for an investment of that size. I didn't tell my friend this, since his money was already sunk and there wasn't much point in telling him to be more paranoid.
This was a real-world security, not some shady garbage floated on the internet. It wasn't strictly a ponzi, since they didn't actually pay anyone anything; the founders just pretty much declared bankruptcy under suspicious circumstances and bailed themselves out.
So points 1-3 apply, but I have to say that getting to know the people behind an investment doesn't prove anything. You just need to have a sixth sense for when you're being conned.
Start with the assumption that you're always being conned. Work backwards from there until you trust somebody. Matthew Wright gave me endless shit for calling Pirate a ponzi, since that whole thing started. "How can you prove it's a ponzi?" He kept asking. Well, prove it isn't. Because until proven otherwise, anyone with their hand out is suspicious.