After the Affordable Care Act went into effect I signed our company up for our state's marketplace. While browsing our plan options, I noticed the url used a scheme like marketplace.org/employers/341/plans.aspx. Of course, I tried changing the number in the url to 342 to see what happened. To my astonishment, it loaded up the next company's plans, including a list of employee names, ages, plan cost, and SSNs. After I…
I think as soon as anything healthcare adjacent comes up most people will feel the need to get very nosey about what you accessed. It's possible they would have needed to file an incident (though, honestly, they should've regardless of what the reporter responded with) and gone through some procedure.
It's unfortunate the guy was a dick about it - but asking the extent of the data you accessed probably isn't unreasonable and may have been legally mandated.