Facebook is, in many ways, the only threat to Google's empire on the web. As such, it's unsurprising that Google's new attempt at social would be seen as a big deal to Facebook – especially when it the new site bears such a striking resemblance to an improved version of Facebook. One of the great risks is that users will simply move all their contacts over to Google+ when it becomes publicly available. To make sure this process isn't too easy, Facebook has blocked a Chrome extension called "Facebook Friend Exporter." Friend Exporter can be used to quickly import your friend information, include contact information and birthdays, to Gmail – and thus, eventually, to Google+. As Mohammad Monsour reported to CNET, "[Facebook] implemented a throttling mechanism that if you visit your ~5 friends in a short period of time, it will remove the email field." This prevents the extension from functioning. Others who have attempted to create similar export tools, including Rafael Laguna, have run into similar problems. Get the full story at Search Engine Watch