Well, due to the current state of world government affairs anyway...
I cannot think of a viable situation that would pay a retarded amount of interest that someone would accept BTC for that wasn't illegal in some way. Either through selling illegal merchandise, services, evading taxation and regulation (hello SEC), or straight up fraud (Ponzi scheme or some kind of scam run by the operator in the outside world). So the person/entity operating the HYIP has every reason to be anonymous. Now, you can be anonymous too so that you reduce your exposure to any possible legal consequences...but then this just encourages the operator to run off with your money at some point.
And to even possibly work, the amount of BTC you invest *must* be converted into the equivalent amount of fiat with interest payments being made in that denomination. Basing your interest payments in BTC has a high likely of eventually fucking you over due to market fluctuations.
So far, I have only seen anonymous operators taking in and paying out in BTC from anonymous people.
I hate government...but you're probably making a bad decision if the operator doesn't share their identity, doesn't tell you how they make their money, and has no evidence of being licensed and filing taxes.
tl;dr: If you keep thinking with the greedy part of your brain, you're going to get hurt.
What you're saying is true of ALL High Yield Investments, not just bitcoin.
Right now according to dividend.com of the top 20 highest yielding stocks
http://www.dividend.com/dividend-stocks/high-dividend-yield-stocks.phpMOST are either highly speculative (REITs, mining ventures etc) or in serious financial trouble and trying to use a higher dividend to increase their share price so they can get loans against shares (ponzi anyone). None of these have any guarantees associated with them ether.
The highest bond yields have always been junk bonds, in fact the term "high yield bond" is a synonym for junk bond. They're extremely speculative investments.
Knowing who is holding your money isn't much help. Everyone knew Bernie Madoff.
The only people who ever benefit from SEC intervention are those who are already financially well off and well connected. Invest in a junk bond and the company collapses, the SEC isn't going to do anything for you, sorry but that agency should be renamed the Special agency for the Elite and well Connected.
Don't read this wrong. I'm not saying that scams are ok, nor do I support any of these HYIPs that I'm aware of (with the possible exception of BDT), but don't think for a second it's limited to bitcoins.
If you want some good reading I suggest you look up what happened to the American dollar during the literal "wild west" years when banks were able to issue their own currency. There is a good reason the founding fathers wrote into the constitution that the government would have to back it's currency with specie (silver/gold) and could not issue fiat. I consider bitcoins a new form of specie.
