Google recently blocked Facebook API access to download Google contacts. To counter this, Facebook found another way "a direct URL that lets you export your contacts, so you don't have to visit Gmail."
A Google spokesperson said that "users often aren't aware that once they've imported their contacts into sites like Facebook they're effectively trapped. We hope that reciprocity will be an important step towards creating a world of true data liberation--and this move will encourage other websites to allow users to automate the export of their contacts as well."
To this, Facebook Platform engineer Mike Vernal responded by defending Facebook's policy and calling it "consistent".
Here's what Google's telling users who would like to download their Gmail contacts' information and import the data into Facebook: