Active Directory users in Windows Phone 7?

Can you use a DirectorySearcher to make an LDAP query via WMI to query users in an Active Directory directly.

E.g. something like:

new System.DirectoryServices.DirectorySearcher(
new DirectoryEntry(
"LDAP://server/dc=mydomain,dc=com",
"administrator",
"password",
AuthenticationTypes.Secure
)
){ Filter = "objectClass=user" }.FindAll();