Such a high interest rates are sign that founders expect for their user base to grow exponentially all the time and cannot be sustained in the real work. It is a cloaked pyramid scheme.
I dare you to start any business and offer interest rates like that.
First of all, I am cryptocurrency supporter and own some of the stuff. Now, governments are not interested in BTC so far, because of it's market size. It is damn to small. They will shutdown some exchanges, but
generally users will be left alone. Governments don't need excuses: they do whatever they want, and count bodies later (prohibition for example).
Now, thinking that some techno innovation will escape their firm grip is not based on a fact:
a) Governments can without problems manufacture BTC ASIC's and overtake the network in a month. I know for certain, that they are able to spend 1 mil USD on developing video overlay chip. If they wanted to make
the fastest BTC ASIC, they are more then capable to do so. Actually, I think they are already mining in limited capacity in order to profit from otherwise untaxable transactions by inducing the artificial inflation to BTC.
b) Full fury of government can only be seen when it happens. Look what happen to LR. Nobody knew it was coming. They had a coordinated action in multiple countries, offline and online.
While I like and support the whole cryptocurrency idea, I urge anyone to be very careful when doing anything related to it and use it as a protocol not as commodity.
A payment of interest (as an extra inducement to get people to join E-Numbered) is not necessarily a sign of anything, although it might contradict their "we're not a bank, we're an e-currency" claims. Do banks offering interest have a 'ring of HYIP?' And with BTC there's a difference between 'secure' with respect to each transaction, vs. anonymous.
It's actually an acceptable compromise to have a system where those who actually are allegedly performing crimes can have their transactions individually traced, while leaving everybody else's holdings alone. The ability to do so takes away the excuse invoked by the government to freeze everybody's accounts and shut down an entire processor over claims about a few people. Bitcoin is secure in the sense of the stability of the algorithm, and in not being subject to a mass shutdown, as is the case with a web-based processor with a central HQ.