Google Abn Amro censure, options express censure, State Street global markets censure just to warm up. From there you shall find the rest. Countless FCMs were fined in the past for lack of disclosure, misleading clients, and short changing clients. I hope you don't imagine their clients to have benefitted from such violations.
A 'dozen' FCMs whose clients lost 'huge chunks' of money? I'd love to see the 'list.'