wp_remote_get SU badge

If try a

$su_response = wp_remote_get($subadge_url);

where the subadge_url =

http://www.stumbleupon.com/hostedbadge.php?s=1&r=http://www.google.com

(see here: http://www.stumbleupon.com/buttons/)

it does not return anything? Or am I using wp_remote_get the wrong way?