See the page at e.g. http://excelsior.gtbrinke.nl/lampionnenoptocht/
Plugin settings: I only enabled the FB button in Posts, changed it to HTML5 (but the problem also occurs with the default xfbml) and enabled Add Hidden Debug Info.
Problem: I have enabled "Secure Browsing" in my FaceBook security settings. Upon loading the FaceBook like button, I get a lot of security warnings/errors in my browser's console log (see below). When disabling "Secure Browsing" on FaceBook, I do not get the errors.
[Error] Blocked a frame with origin "http://www.facebook.com" from accessing a frame with origin "http://excelsior.gtbrinke.nl". Protocols, domains, and ports must match. global code (like.php, line 1) [Error] Blocked a frame with origin "http://www.facebook.com" from accessing a frame with origin "https://www.facebook.com". The frame requesting access has a protocol of "http", the frame being accessed has a protocol of "https". Protocols must match. (x25)
The first error occurs only once, but every time I move my mouse (especially when hovering over the buttons) and/or click the buttons, tens of these errors pop up. I think it even prevented the buttons loading in one case, although I can't remember the settings and cannot reproduce that particular issue.
Is there anything I—or you—can do to make the plugin more secure, or at least prevent these security errors to occur?