Facebook Temporarily Blocks All Ow.ly URL Shortener Links

Earlier today, Facebook temporarily blocked URLs shortened with the Ow.ly domain used by HootSuite, possibly in response to a worm distributed in an Ow.ly link. The worm’s shortened URL contains the Facebook query string “?=www.facebook.com/photo.php” which could fool users into thinking they were visiting a Facebook page. All Ow.ly links on Facebook, legitimate and malicious, temporarily led to Facebook’s blocked abusive site error page.