IMO, brokers should do like casinos: Casinos have security cameras. They ban card counters and cheats. The casinos compare notes with one another. They refuse service to crooks and card counters. They work with State and Federal law enforcement to catch and prosecute crooks. Brokers? They have account numbers with passwords. They talk with operators to work out stock deals. They allow just about anyone to open a brokerage account. If someone scammed another broker, there is nobody comparing notes. It's a brand new day for the new account holder.