Ok, scam & ponzi things aside.

The only reason somebody puts a timeframe on withdrawals is cause they don't have money to pay. He or She, currently has 150BTC in the account but how much of that needs to be paid out. Monday, Tuesday & Todays and i bet he doesn't have that much. Bottom line he is trading/operating while insolvent which is also criminal and by default proves its a ponzi. You can't take from peter to pay paul.