Do you know everyone or who they are or what they are going through? Who said it is only for farm workers, or married or crime reporters? Are you on TPS? If you have a legal status this shouldn't concern you or if you are not on a removal proceeding. It appears you are fine, legal status wise, so don't try to discourage other people.

And also, who said you need a police report for everything? This post is also for people who have gone through trafficking including by employers or other types. If you don't know who then maybe you have not been gone through that experience. If you have not gone that experience, doesn't mean other people didn't.

I can't explain it to you, google it and talk to a lawyer.

My recommendation to other people, please look for a valid option like some of the visa examples I have given above.