The data file, which was seeded on to BitTorrent filesharing services earlier this week by Ron Bowes, a security consultant, is around 2.8 gigabytes large, and contains the public Facebook profiles of 100 million users of the social networking site – around 20% of Facebook's global membership.

Facebook says that the data that the Nmap securitry researcher collected is in the public domain and no privacy rules have been breached.

In its press statement on the saga, Facebook says that users have the right to share only what they want, with whom they want, and when they want.

"In this case, information that people have agreed to make public was collected by a single researcher and already exists in Google, Bing, other search engines, as well as on Facebook", said the statement, adding that no private data has been compromised.

Commenting on the Facebook file's propagation on filesharing sites, Amichai Shulman, chief technology officer with data security specialist Imperva noted that he has been saying for some time that you should never publish anything on a social networking service – no matter what the privacy settings – that you would not want to be made public.

The publishing of this harvested file clearly proves why, he said.

The BBC newswire, meanwhile, quotes Simon Davies, the director of Privacy International, as saying that Facebook had been given ample warning that something like this would happen.

"Facebook should have anticipated this attack and put measures in place to prevent it", he told the BBC.

"It is inconceivable that a firm with hundreds of engineers couldn't have imagined a trawl of this magnitude and there's an argument to be heard that Facebook have acted with negligence", he added.

According to Davies, who is a long-standing supporter of privacy on the internet, the data file's release adds to the confusion about privacy settings on sites like Facebook.

"People did not understand the privacy settings and this is the result", he told the BBC, referring to the revision of Facebook's privacy settings earlier this year.