MULTISITE - only have to sign up on main site

I want to create subdomains for chapters but members only have to sign up on main site and then have access to all sites. How do I set S2 up to do this? I do not want S2 to be an active on the subdomains?
In other words...sign up for access at ABC Organization
membership gives you access to Atlanta.ABC, NewYork.ABC, Miami.ABC....
I want the "chapters" to be able to post events and blog, but not have access to member info
is there a way to do this? I have been struggling with this for over a week. Please help!
In other words...sign up for access at ABC Organization
membership gives you access to Atlanta.ABC, NewYork.ABC, Miami.ABC....
I want the "chapters" to be able to post events and blog, but not have access to member info
is there a way to do this? I have been struggling with this for over a week. Please help!