People Picker at site collection [ Q / A ] - 1

Question :
The customer is using WSS in an extranet scenario using both Forms and AD authentication to manage accounts for their internal employees and external clients and partners.

Currently, they manage 80-100 client team sites in one site collection and have run into a problem when using a task list. The issue stems from the fact that when they are assigning a task to a user on that site, there is a people picker control in the list that allow them to select users. Currently the list shows ‘all users’ (Forms & AD) and they only want to list users that are ‘members’ or a part of the team site.

This is an issue because they have NDA’s with their clients and it is competitive information. One client should never find out the other client exists…

We believe the only solution to resolve this is to migrate or move the sites into separate site collections, but are curious if Microsoft has any other recommendations before we turn down that path… It would require effort to move the sites and we want to make sure this is the best solution before we move forward with that approach.

Answer
One way could be configuring the people picker to show only users from the site collection membership (Peoplepicker-onlysearchwithinsitecollection): http://technet.microsoft.com/en-us/library/cc261988.aspx