Is there a licence issue using the “All authorised users” type of permission group?

Question

Is there a licence issue using the "All authorised users" type of permission group?

Does it require extra CALs or is it just a synonym that doesn't matter?

Answer 1

All authenticated users will grant everyone with a valid username/AD account access to the site. If you have CALs for everyone in your company, then there won't be an issue. If you only have a few CALs for SP access for a select group of users and open it up to everyone, you would be in violation of the licensing terms should you get audited.