The fight heated up. After Google has blocked the import data for the Contacts API Gmail (and apparently the Orkut too), the Facebook decided to counter-attack the less friendly as possible: providing an alternative to the Contacts API. Instead of creating your own tool to export emails like Google so delicately required, the social network now offers an alternative that involves downloading a file .csv.
When a user tries to find your friends and Google return any result, Facebook will display the screen above. The big blue button Download Your Contacts low, if the user is logged into Gmail, a .csv file with all the addresses email. This file is then selected and sent to Facebook, seeking friends, offers the option to add them automatically and gives the alternative to send invitations to those who have not joined the network.
According to an engineer consulted by TechCrunch, this technique can be blocked if Google wants. But that would endanger other tools that make use of this function.
One reader even said yesterday that the export of friends emails on Facebook is possible via Yahoo! Mail, but this feature does not seem to work for everyone. The Facebook API does not reveal email addresses officially, then it is likely that Yahoo! is using some alternative method or undocumented.