I'm looking to understand the connection between the User Profile Service and the hidden User Information List.
Here's what I'm experiencing.
New SharePoint 2013 farm with a migrated UPS from a SharePoint 2010 environment. The UPS is functioning properly. When I create a new site collection, I expect that the hidden list to be empty except for the first few accounts that touch it. However I've got every group and user from my AD environment in there.
I thought I understood the hidden list to only retain people who have accessed the site. How did the entire AD get in there?