Earlier quoted context omitted.
I agree with the sentiment here, but I'm not sure how that could ever really be implemented. Our laws shouldn't punish people for honestly doing the best they know how to, especially with a caveat that it doesn't matter if it was industry standard. Not only is that confusing and at serious risk of punishing all the wrong people, it creates incentives to help hack your competition and throw them to the legal wolves.
The government should assign punishing penalties for leaks that scale with the quantity and invasiveness of the data, and help grow an insurance industry for paying those penalties. That way, the law dictates how "bad" leaks are with fines, and the insurers encourage/require best practices. Externalities become internalities.
If anything, an insurance policy for it allows the companies to externalize and distribute the fines.