It sounds like they're asking for something and people don't have to give it if they don't want to. Facebook may stop doing business with them, but that's between them and Facebook.
You're talking like Facebook would have arrested them or something if they didn't show it. I'm not sure that's what's going on here. They're just asking for something. Say 'no' if you don't want to show them.
Unless they're showing up repeatedly or at weird hours of day but that's not implied at all. Sounds like it's just a business visit?