How to Protect Your Money From Cyber Criminals

This question is from user name Victoria F from the Boglehead's forums who writes, what protections do we have in Vanguard and Fidelity accounts if cyber criminals break into them? Let's assume that we use complex passwords, don't share our passwords with others and use two-factor authentication or multi-factor authentication as we just talked about by the brokerage. Even I'm curious, what are your thoughts on having your money at Tukasdodians? That way, if cyber criminals happen to break into one of those Tustodians, I'll still have money somewhere else.