There's more legal recourse for a mistake from law enforcement, and furthermore, they aren't going to show cases where you were acquitted. In my case, the background check company reported a crime that I HAD been arrested for but found not guilty of. Background check companies don't do their due diligence in making sure that the records they gather are still valid. I wanted very much to sue the company that cost me that job opportunity, but they've covered their bases enough to shift accountability to the customer.

Basically, they put an asterisk next to their reports saying to take them with a grain of salt. But that doesn't change the damage done by a potential employer getting a peak into your past that they never should have gotten.

Edit: fixed some typos