The following warning was enclosed in my latest E*Trade account statements.
You can lose more funds than you deposit in your margin account. We can force the sale of securities and other assets in your account(s). We can sell your securities and assets without contacting you. If the firm takes action to meet a margin call on your behalf, you will not have the ability to choose which securities are liquidated. We can increase your "house" maintenance margin requirements at any time and are not required to provide you with advance written notice. You are not entitled to an extension of time on a margin call.