Facebook has hit back at attempts by its members to transfer their contact information to Plaxo's address-book-management service.

The new Plaxo feature, which is in early-stage testing, is called Facebook Importer, and recently Plaxo reached out to a few hand-picked external users to try it out.

"Facebook has been turning into a new kind of address book, and we wanted to help our users move their data in and out of that service," said John McCrea, Plaxo's marketing vice president.

At least one of those users, well-known technology blogger Robert Scoble had his Facebook account closed for using the Plaxo tool. The incident may surprise some Facebook followers since the company's CEO recently said he wants to let users export their data to other online services.

Scoble reported on his blog that he had received a notice from Facebook saying he had violated the site's terms of service. He had Facebook's maximum of 5,000 friends on his account. However, Scoble later announced that Facebook had reinstated his account.

Plaxo planned to roll out the feature later this month to users of its Plaxo Pulse service, but those plans are now up in the air because the company doesn't want other Facebook members to get kicked out of the site like Scoble, McCrea said. He acknowledged that Plaxo didn't consult with Facebook while designing and testing this feature.

Plaxo's Facebook Importer can't function properly using just the application programming interfaces (APIs) that Facebook has made available, to third parties interested in creating applications for its social networking site, said Joseph Smarr, Plaxo's chief platform architect.

"While Facebook has ostensibly created these open APIs to use both off their site and, with their platform, on their site, they've gone to fairly great lengths to make sure you can't get out the data you need to take your friends' list with you," Smarr said.

Specifically, Facebook's APIs don't allow third-party applications to capture members' email addresses, a key data point for address books, so Plaxo worked around this limitation by doing optical character recognition, or "scraping," to capture this information, Smarr said.

"We used their APIs to the extent possible, but if they're not providing the data that our users want, we have to augment that. And it's no different from them scraping Gmail and doing a Gmail import. It's fairly wide industry practice at this point," Smarr said.

Facebook's walled-garden position strikes Plaxo as inconsistent and contradictory, since Facebook allows its members to import address-book data from external email services and applications.

"This is obviously functionality that Facebook is using to be able to pull in data from all these other sources, so it strikes us as a case of what's good for the goose isn't good for the gander," Smarr said.

By contrast, Plaxo has a similar feature that lets members of the LinkedIn social network move their contacts' data out to Plaxo, McCrea said.

The spat between Plaxo and Facebook highlights the thorny issue of data portability in social networking sites. In fact, Facebook CEO Mark Zuckerberg was asked for his position on this matter in October at the Web 2.0 Summit, and he spoke in favour of making data portable for his site's members.

At the time, Zuckerberg said Facebook members should be able to move the data they keep in their profiles to other online services if they want. He even went as far as to admit that it's "a flaw in the system" of Facebook that doesn't let them do this today.

"It's the users' data. We want to [make it portable.] That's the goal," he said, but, when pressed to provide a timetable for when Facebook might do this, he refrained from making a deadline commitment.

Zuckerberg's comments at Web 2.0, along with a series of Facebook moves to open itself up to external developers, prompted Plaxo to develop the importer, so the response to the feature caught the company by surprise, McCrea said.

According to Scoble's blog posts, Facebook told him via email that his account was suspended because the company detected that he was running "automated scripts," which Facebook forbids for security reasons. In the last Facebook email Scoble quotes in his blog, Facebook said it decided to reactivate his account because he told them he wouldn't run the Plaxo script again, nor any like it.

Incidentally, Scoble managed to transfer his Facebook friends' data out to Plaxo Pulse, so the feature apparently works as intended.