XML-RPC does not display password protected posts

I Worte a simple plugin to list posts from a certain category but it omits password protected posts. I added a filter to display all posts regardless of the password, but it doesn’t work.

<?php
function xml_add_method( $methods ) {
    $methods['zio.categoryVideos'] = 'get_category_videos';
    return $methods;
}

function allPosts($where) {
	$where .= " AND post_password like '%' ";
	return $where;
}

function get_category_videos( $args ) {
	global $post;
	$args = array('numberposts' => 50,'cat' => $args );
	add_filter('posts_where', 'allPosts');
	$myposts = query_posts( $args );
	$struct = array( );

	foreach( $myposts as $post ) :	setup_postdata($post);
		$id = get_the_id();
		$guid = get_permalink();
		$title = get_the_title();	

		$struct[] = array(
			'id'		=> $id,
			'guid'		=> $guid,
			'title'		=> $title,
			'thumbnail'	=>	$thumb
		);
	endforeach;

    return $struct;
}

add_filter( 'xmlrpc_methods', 'xml_add_method' );
?>