Index: wp-admin/network/users.php
===================================================================
--- wp-admin/network/users.php	(revision 24432)
+++ wp-admin/network/users.php	(working copy)
@@ -50,7 +50,10 @@
 				<br /><fieldset><p><legend><?php printf( __( "What should be done with posts owned by <em>%s</em>?" ), $delete_user->user_login ); ?></legend></p>
 				<?php
 				foreach ( (array) $blogs as $key => $details ) {
-					$blog_users = get_users( array( 'blog_id' => $details->userblog_id ) );
+					$default 	= array( 'blog_id' => $details->userblog_id );
+					$args 		= array_merge( apply_filters( 'network_delete_user_dropdown', array() ), $default );
+
+					$blog_users = get_users( $args );
 					if ( is_array( $blog_users ) && !empty( $blog_users ) ) {
 						$user_site = "<a href='" . esc_url( get_home_url( $details->userblog_id ) ) . "'>{$details->blogname}</a>";
 						$user_dropdown = "<select name='blog[$val][{$key}]'>";