bitcoinrain was basically a ponzi and mercadobitcoin(one exchange donator to bitcoin foundation) used adulterated fiat balance to gather coins. The operator of both sites excuse was this: he put all coins of bitcoirain in one account of his exchange www.mercadobitcoin.com.br because he though it was safer this way so he could go in a trip but unfortunatelly the website was hacked in his absence.
guess what, the "hacking" event occurred during the bubble. withdrawals from his ponzi(bitcoinrain) were already halted many days prior the hacking event.
After the heist of his exchange account that also held his ponzi coins no addresses were made public and since we is a known person and already threatened by government he tries to keep this as silent as possible, thus he aims at trying to keep everyone that had coins with him under control. His is promissing one payment plan pricing the coins at 180 brazilians real, about 80USD.
He also held hostage any fiat balance people had on his exchange for more than 3 months after bubble popped, which is the reason I say he used to manipulate the sellings.
profile of the suspect: https://bitcointalksearch.org/user/leandro-cesar-10275
Every coin sent to bitcoin rain accounts would first go to this address:
https://blockchain.info/address/1FuiZdyNvJPy5pPdJMSNSoUhme3D6FmPpp
I just found this thread and will compile a more detailed version of the facts later.
Has been added. Others coming soon.