With the big rise in CryptoCurrency Market Capitalizations one can expect a rise in people trying to take it from your hands.
Recently, more of these double your bitcoin and forced matrix ETHerium systems has sprung up.
One that just recently stopped and ran off with, at the time, almost USD$ 7 Mil was BitcoinsBrain. You can see some of the transactions that happened still days after they shut down shop and stole money from people's hopes Blockchain Wallet.
Others that looked like they were very legit, suddenly started to charge exuberant "extortion" (admin) fees anddays later stopped their "trading" GladiaCoin - Double your bitcoin in 90 days. (If the site is still up that is. It was down for a few days until a few hours ago.)
The funny thing is that just a few days ago, another one - that looked pretty much EXACTLY the same (with a admin fee already set in place) popped up yesterday - TwiceCoin (What is the chance it is the same people doing this?)
How many more is popping up and how many is from the same swindling owners? One cannot say.... Because none of them is backed by "owners" that can be held accountable...
I suppose that is the "good" and the "bad" about blockchain crypto currencies in one sentence...
I think the rule of thumb to follow is this:
From the wise words of my father:
When something is too good to be true,
It usually is...
Final thought:
Be careful out there. There are people out to steal your coins... Because currencies is unregulated (good), they can steal it and get away with it (bad). But it is up to you to keep your wallets safe (good) in order for a bank/government to NOT have have control over it (very good)...