…compliments of stupidity.
The description of the incident says it all, but I will summarize for your convenience:
An Ameriprise (American Express Financial Advisors, renamed) employee was carrying around 200,000+ brokerage account records, on a laptop, unencrypted. He or she left the laptop in a parked car (likely in plain sight), and someone broke into the car and took it.
Stupid points, made more so in their combination: laptop, unencrypted data, parked car. Its so dumb, I wonder if there is more to this story.