One year ago:
“Our badge/widget isn’t compatible with https sites; there are no plans at this time to change it.”
https://getsatisfaction.com/stumbleupon_help_center/topics/badge_widget_https_mixed_content_problem
Wow, how to ignore an ever growing set of your content base, specifically those most up-to-date and therefore probably interesting, in one sweeping statement.
Must be trying to compete with Reddit for the foot shooting prize.