Few days ago, I enabled the option of secure connection (https) on Facebook. However today, I notice that Facebook badge cannot work well on the 3rd party website. After checking the badge HTML code provided by Facebook, I find out 3 "http" links replaced by "https" links. One of the 3 links is "https://badge.facebook.com/badge/1019865928.111.461839450.png" . Visiting this URL on Chrome, it prompts: SSL Error Clicking "Proceed anyway", the badge seems good. Therefore, it seems like Facebook's SSL certification works only for "www.facebook.com" but doesn't for "badge.facebook.com". And the browser refuses to visit "https://badge.facebook.com" automatically. The alternative solution is that I replace "https://badge.facebook.com" by "https://www.facebook.com" in the code and the badge works well. But it's very hard work to modify all the badges embed into so many webpages.