I was just wondering what types of information a landlord may obtain about a perspective tenant and how it used against you?

Well it is not "used" against you, and it is not "used" for you, it is merely used to decide if they wish to rent to you or not.
They will see all of your debts, and how you pay for each of them, also your last known employer is often listed.

You should run one for yourself.

I was just wondering what types of information a landlord may obtain about a perspective tenant and how it used against you?


I have also been asked to run criminal checks on prospective tenants as part of the background checks.

I own rental property - I don't use the information "against" the prospective tenant. I use it to help me determine the good tenants... and the bad tenants.

The landlord may obtain ANY information that is part of the public record. That information is used to determine if the person is a good risk as a tenant. Specifically, a landlord would want to know whether the prospective tenant pays his bills on time, was ever evicted from a previous home, has a criminal record etc.