Well, FXCM wore the cost of their customers positions during the Swiss uncoupling not to long ago. Ran into many Millions of $ total. They now have a very robust risk management strategy ahead of potential risk events. It would have broken many others but FXCM had been well capitalized and they got through it. FXCM didn't create the risk they were exposed to, it was a disproportionate number of their customers who had no idea how to undertake appropriate risk management for THEIR OWN CUSTOMER ACCOUNT SIZE. The customers just had no idea what they were doing and FXCM was the backstop for those customers. Stupid traders BREAK brokerages. Stupid brokerages allow stupid traders to break them. You can't blame a broker for having robust risk management strategies. If they didn't, we would ALL still be stuck back in the bad old days of having limited brokers to choose from and really shitty options where the customer looses out ALL the time. Imagine if the only way to trade was to still ring up a broker and place your trade manually. To get out was the same with a guarantee that you would be filled within 1 HOUR of your call! LOL, good luck day trading like that. Good brokers limit THEIR exposure during high risk events. It means that they PROTECT their COLLECTIVE customer accounts. If a broker goes bust, you will suddenly find out what sort of "segregated" customer accounts they truly maintained when ALL customers can either get their account funds back or they can't. If you don't like your current broker, go somewhere else. Only customers leaving will demonstrate a broker needs to adapt and change.
I guess I assumed OP knew I was referring to Fxcm as an example. You explained it very well, could not agree more.