Yes, you should be concerned. When a local bank did something similar, I reported them to the Federal Reserve for rights violations and they were promptly swarmed with investigators checking into their practices.

A brokerage has some government organization that overlooks them. I’m not sure what it is offhand, but I would report them to that organization. Safe keeping of personal information is a federal requirement and not doing so is a violation of federal law. It violates you as a person and set s you up for how knows what.