There is a long, long history of financial scams. That's why the handling of other people's money is regulated. FINRA fines about one broker a day, year in and year out. Even with regulation, there are problems, but today in the US you can often get your money back. Bank failures occur, stock brokerages fail, and the SIPC and the FDIC pay off the losses up to $250K per person. Madoff's victims already have about half their money back, after years of litigation and clawbacks. Madoff himself, of course, is in the federal pen at Butner, North Carolina.
The Bitcoin world thinks it doesn't need regulation. About half of Bitcoin brokers, and most of the Bitcoin online wallet companies, have gone bust, most of them taking customer assets with them. Any questions?