Does anyone know? Spiders?

[calorie]

When a spider visits your site, it sees the same content that a guest would see. If you show the spider something different than a guest would see, then what you are doing is considered cloaking, and it might get your site banned from search engines. That said, some sites have a legitimate reason to cloak, for example, geo-targeting. However, if you show guests a no permission page, but show spiders the actual content, those two pages are certainly different enough to IMO land you in the ban zone.