settings per user per location

I'm looking for an interface that will do the following task. I have a table with a list of locations and settings for each location by user.

So, if I pick a user "John Doe", I'm presented with the following grid:

Location | Add | Read | Delete | Receive notifications

New York   [ ]   [x]     [ ]            [x]
Seattle    [x]   [ ]     [ ]            [ ]  
.......

This works great, but I have to pick each user separately. And number of users can be >100. Is there a way to add users to this table so I can configure all users at once without selecting each user separately? What UX designs/principles can be used?

Thanks!