Index: wp-admin/js/media.js
===================================================================
--- wp-admin/js/media.js	(revision 37539)
+++ wp-admin/js/media.js	(working copy)
@@ -99,9 +99,20 @@
 		$( '#find-posts-close' ).click( findPosts.close );
 		$( '#doaction, #doaction2' ).click( function( event ) {
 			$( 'select[name^="action"]' ).each( function() {
-				if ( $(this).val() === 'attach' ) {
+				var optionValue = $( this ).val();
+
+				switch( optionValue ) {
+				case 'attach':
 					event.preventDefault();
 					findPosts.open();
+					break;
+				case 'delete':
+					if ( ! showNotice.warn() ) {
+						event.preventDefault();
+					}
+					break;
+				default:
+					break;
 				}
 			});
 		});