[Nevadaref]

As the officials are independent contractors, not employees of the state office or school district, background checks are not proper. I'm not giving my personal information to these people who are not my employer. Furthermore, I have no control over how they safeguard this information.
Over the past two years I convinced our state office that they have no need for our SS#. I'm certainly not going to backtrack now.
Lastly, the issue of who pays for it is huge. If the school people want the background check, then they would need to come up with the funds for it.

In the past five years, I've seen several reports of teachers having misconduct issues with students and they are employees and have background checks. So they aren't effective anyway.