Yes E*trade abides by that rule.. which states you must have 25K in your brokerage account in order to day trade consistently (more than 3 round trips within a 5 trading day period).
If you do not have 25K in your account and you make more than 3 round trips within those 5 trading days.. you will be flagged as a day trader and must meet a call which is a minimum of 25K to have your account unrestricted.