Add rel nofollow to tags, author, date, thumbnails

rel_nofollow_to_elements.php

add_filter('tc_display_post_thumbnail', 'strip_and_nofollow');
add_filter('tc_tag_list', 'strip_and_nofollow');
add_filter('tc_date_meta', 'strip_and_nofollow', 9999);
add_filter('tc_show_link_to_post_after_metas', 'strip_and_nofollow', 9999);
add_filter('tc_author_meta', 'strip_and_nofollow', 9999);

function strip_and_nofollow($text){
    $text = stripslashes($text);
    $text = preg_replace_callback('|<a (.+?)>|i', 'strip_and_nofollow_callback', $text);
    return($text);
}

function strip_and_nofollow_callback($matches){
    $text = $matches[1];
    $text = str_replace(array(' rel="nofollow"', " rel='nofollow'"), '', $text);
    $count = 0;
    $text = preg_replace( array( '|(.+?rel=".+?)"|',"|(.+?rel='.+?)'|"), array('$1 nofollow"', "$1 nofollow'"), $text, 1, $count);
    if ( ! $count )
        $text .=' rel="nofollow"';
    return '<a ' . $text . ' >';
}