Index: wp-admin/includes/class-wp-ms-users-list-table.php
===================================================================
--- wp-admin/includes/class-wp-ms-users-list-table.php	(revision 24809)
+++ wp-admin/includes/class-wp-ms-users-list-table.php	(working copy)
@@ -186,6 +186,10 @@
 								$actions['edit'] = '<a href="' . $edit_link . '">' . __( 'Edit' ) . '</a>';
 
 								if ( current_user_can( 'delete_user', $user->ID ) && ! in_array( $user->user_login, $super_admins ) ) {
+									if ( 0 == $user->spam )
+										$actions['spamuser'] = '<span class="spam"><a href="' . $delete = esc_url( network_admin_url( add_query_arg( '_wp_http_referer', urlencode( wp_unslash( $_SERVER['REQUEST_URI'] ) ), wp_nonce_url( 'users.php', 'spamuser' ) . '&amp;action=spamuser&amp;id=' . $user->ID ) ) ) . '" class="spam">' . __( 'Spam' ) . '</a></span>';
+									else 
+										$actions['unspamuser'] = '<span class="spam"><a href="' . $delete = esc_url( network_admin_url( add_query_arg( '_wp_http_referer', urlencode( wp_unslash( $_SERVER['REQUEST_URI'] ) ), wp_nonce_url( 'users.php', 'unspamuser' ) . '&amp;action=unspamuser&amp;id=' . $user->ID ) ) ) . '" class="spam">' . __( 'Not Spam' ) . '</a></span>';
 									$actions['delete'] = '<a href="' . $delete = esc_url( network_admin_url( add_query_arg( '_wp_http_referer', urlencode( wp_unslash( $_SERVER['REQUEST_URI'] ) ), wp_nonce_url( 'users.php', 'deleteuser' ) . '&amp;action=deleteuser&amp;id=' . $user->ID ) ) ) . '" class="delete">' . __( 'Delete' ) . '</a>';
 								}
 
Index: wp-admin/network/users.php
===================================================================
--- wp-admin/network/users.php	(revision 24809)
+++ wp-admin/network/users.php	(working copy)
@@ -88,12 +88,14 @@
 
 if ( isset( $_GET['action'] ) ) {
 	do_action( 'wpmuadminedit' , '' );
+	
+	$mark_sites_for_spam_user = apply_filters( 'mark_sites_for_spam_user' , false , $val );
 
 	switch ( $_GET['action'] ) {
+
 		case 'deleteuser':
 			if ( ! current_user_can( 'manage_network_users' ) )
 				wp_die( __( 'You do not have permission to access this page.' ) );
-
 			check_admin_referer( 'deleteuser' );
 
 			$id = intval( $_GET['id'] );
@@ -111,7 +113,64 @@
 			}
 			exit();
 		break;
+		
+		case 'spamuser':
+			
+			if ( ! current_user_can( 'edit_users' ) ) 
+				wp_die( __( 'You do not have permission to access this page.' ) ); 
+			check_admin_referer( 'spamuser' );
+			
+			$id = intval( $_GET['id'] );			
+			$user = get_userdata( $id );
+			if ( false === $user || is_super_admin( $user->ID ) ) 
+				continue;
+				
+			$blogs = get_blogs_of_user( $id, true );
+			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( $id, 'spam', '1' );
+			wp_safe_redirect( add_query_arg( array( 'updated' => 'true', 'action' => $userfunction ), wp_get_referer() ) );
+		
+		break;
+		
+		case 'unspamuser' :	
+			
+			if ( ! current_user_can( 'edit_users' ) ) 
+				wp_die( __( 'You do not have permission to access this page.' ) ); 
+			check_admin_referer( 'unspamuser' );
+			
+			$id = intval( $_GET['id'] );
+			$user = get_userdata( $id );
+			if ( false === $user || is_super_admin( $user->ID ) ) 
+				continue;
+				
+			$blogs = get_blogs_of_user( $id, true );
+			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( $id, 'spam', '0' );
+			wp_safe_redirect( add_query_arg( array( 'updated' => 'true', 'action' => $userfunction ), wp_get_referer() ) );
 
+		break;
+		
 		case 'allusers':
 			if ( !current_user_can( 'manage_network_users' ) )
 				wp_die( __( 'You do not have permission to access this page.' ) );
@@ -123,7 +182,14 @@
 				$userfunction = '';
 
 				foreach ( (array) $_POST['allusers'] as $key => $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 +205,40 @@
 							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;
 						}