While many of the brokers, may not steal your money, I believe your money is being used to fund and pay the winners when there reserves are depleted. I believe this is the reason many of them offer the 50% deposit bonuses, and sometimes more if you deposit today or by a particular date.
With that said, the only (U.S.) regulated exchange that trades binary options and bull spreads is Nadex. You can open an account with them and make alot more than 70-95% per trade. They may not have 1, or 30 minutes "expiry times", however, you can open and close positions anytime during the contract therefore you don't have to wait until it expires to profit or cut your losses. Also, it's not the same "user friendly" platform that the other "brokers" have, so it may have a learning curve (they do offer a free demo & there are videos on youtube from Nadex); but I feel much more safe knowing that I can see the actual liquidity and actual prices of the contracts. Also, if I need to make a withdrawal it takes 3-5 for an ACH, or next day for a wire. So my money is safe.
BTW, I don't work for, nor am I compensated by Nadex for this info. So there you have it. :) So if you are interested, do your research and check it out for yourself, and then decide what is best for you.
Here's a screenshot
http://i1074.photobucket.com/albums/w416/PrvIII56/5f23dec1.jpg
Hope that helps! :)
Anyway, back to the Binary Options Bully request, can anyone share? I am interested in checking it out.