Subject: Re: I bet against BRK
Mark, Oscar and Rayvt are correct. There once (2-4 years ago?) was a lengthy discussion here about brokerage risks.

Results:
a) With a margin account your positions are at the named risk if your broker goes under.
b) Even without that it's not 100% sure that there is no risk. That additionally requires the shares to be registered in your name (which was Munger's point which initiated the discussion).

If wrong the people that participated in that discussion please might correct me.