Recently, a client expressed a concern about what users could see when they use the People Picker web control in SharePoint. When the address book pops up, you can see all the users in Active Directory. This client is using SharePoint as an external collaboration tool with their own clients. Since these users are external to the company, they only want them to see users that are site collection specific. To allow this to happen, certain properties can be set on the People Picker using STSADM. Below is a TechNet article from Microsoft that explains what properties you can set and how to set them.
The peoplepicker properties are part of the setproperty and getproperty operations. The syntax for the setproperty operation is:
stsadm -o setproperty
-propertyname <property name>
-propertyvalue <property value>
[-url] <URL>
The syntax for the getproperty operation is:
stsadm -o getproperty
-propertyname <property name>
[-url] <URL>
Note:
You can substitute -pn for -propertyname and -pv for -propertyvalue.
The following table describes the peoplepicker properties.
Properties
Peoplepicker-activedirectorysearchtimeout
Configures the timeout when a query is issued to Active Directory.
Peoplepicker-distributionlistsearchdomains
Restricts the search of a distribution list to a specific subset of domains.
Peoplepicker-nowindowsaccountsfornonwindowsauthenticationmode
Specifies not to search Active Directory when the current port is using forms-based authentication.
Peoplepicker-onlysearchwithinsitecollection
Displays only users that are members of the site collection.
Peoplepicker-searchadcustomquery
Permits the administrator to set the custom query that is sent to Active Directory.
Peoplepicker-searchadforests
Permits a user to search from a second one-way trusted forest or domain.
You can find the article here:
http://technet.microsoft.com/en-us/library/cc263318.aspx