Sometimes people get a bit carried away, typing in massively long strings into the post title. This is often just after they have learnt that the WordPress slug creates a pretty permalink that is good for SEO. The idea that focussing keywords is stronger than diluting them with everything under the sun seems to take a little while longer to sink in.

You can pop this little snippet in your functions.php and it will restrict the character count, word count and also automatically re-set the post status back to draft.

Restrict Post Title Length

add_action( 'publish_post', 'tcb_restrict_post_title', 11, 2 );
function tcb_restrict_post_title( $post_id, $post ){
  $title = $post->post_title;
  $MAX_WORDS    = 8;
  $MAX_CHARS    = 50;
  $err_mess     = '';
  $set_to_draft = 1;

  if( $MAX_WORDS && str_word_count( $title ) > $MAX_WORDS )
    $err_mess .= " Your post title exceeds maximum word count ({$MAX_WORDS}).";

  if( $MAX_CHARS && strlen( $title ) > $MAX_CHARS )
    $err_mess .= " Your post title exceeds the maximum character count({$MAX_CHARS}).";

  if( $err_mess ) :
    if( $set_to_draft )
      wp_update_post( array( 'ID'=>$post_id, 'post_status'=>'draft' ) );
    wp_die( __($err_mess, 'tcb') );
  endif;

  return $post_id;
}

You can toggle setting the draft status off and on easily with $set_to_draft, and if you want to be more or less restrictive on your word and characters counts, just change the numbers in $MAX_WORDS and $MAX_CHARS.