Index: wp-admin/network/users.php
===================================================================
--- wp-admin/network/users.php	(revision 24809)
+++ wp-admin/network/users.php	(working copy)
@@ -123,7 +123,16 @@
 				$userfunction = '';
 
 				foreach ( (array) $_POST['allusers'] as $key => $val ) {
+		
+					$mark_sites_for_spam_user = apply_filters( 'mark_sites_for_spam_user' , false , $val );
+		
 					if ( !empty( $val ) ) {
+				
+						$user = get_userdata( $val );
+
+						if ( false === $user || is_super_admin( $user->ID ) ) 
+							continue;
+
 						switch ( $doaction ) {
 							case 'delete':
 								if ( ! current_user_can( 'delete_users' ) )
@@ -139,25 +148,40 @@
 							break;
 
 							case 'spam':
-								$user = get_userdata( $val );
-								if ( is_super_admin( $user->ID ) )
-									wp_die( sprintf( __( 'Warning! User cannot be modified. The user %s is a network administrator.' ), esc_html( $user->user_login ) ) );
-
+								if ( ! current_user_can( 'edit_users' ) ) 
+									wp_die( __( 'You do not have permission to access this page.' ) ); 
 								$userfunction = 'all_spam';
 								$blogs = get_blogs_of_user( $val, true );
-								foreach ( (array) $blogs as $key => $details ) {
-									if ( $details->userblog_id != $current_site->blog_id ) // main blog not a spam !
+								if ( $mark_sites_for_spam_user ) {
+									foreach ( (array) $blogs as $key => $details ) {
+										// do not mark main site
+										if ( $details->userblog_id == $current_site->blog_id )
+											continue;
+										// only if admin email is same as user
+										if (  $user->data->user_email != get_blog_option ( $details->userblog_id , 'admin_email' ) )
+											continue;
 										update_blog_status( $details->userblog_id, 'spam', '1' );
+									}
 								}
 								update_user_status( $val, 'spam', '1' );
 							break;
 
 							case 'notspam':
+								if ( ! current_user_can( 'edit_users' ) ) 
+									wp_die( __( 'You do not have permission to access this page.' ) ); 
 								$userfunction = 'all_notspam';
 								$blogs = get_blogs_of_user( $val, true );
-								foreach ( (array) $blogs as $key => $details )
-									update_blog_status( $details->userblog_id, 'spam', '0' );
-
+								if ( $mark_sites_for_spam_user ) {
+									foreach ( (array) $blogs as $key => $details ) {
+										// do not mark main site
+										if ( $details->userblog_id == $current_site->blog_id )
+											continue;
+										// only if admin email is same as user
+										if (  $user->data->user_email != get_blog_option ( $details->userblog_id , 'admin_email' ) )
+											continue;
+										update_blog_status( $details->userblog_id, 'spam', '0' );
+									}
+								}
 								update_user_status( $val, 'spam', '0' );
 							break;
 						}