A lawyer for Facebook accused Belgium's data privacy watchdog of waging a "public vendetta" against the social media giant in a court clash over the legality of measures the company says help combat thousands of hacking attacks every day.

Facebook's Ireland-based European headquarters "repeatedly tried to engage" with the Belgian data protection commission, but whatever the company does "it's never enough" for the authority, Paul Lefebvre, a lawyer representing Facebook, told the Brussels appeals court.

Information storage

Facebook is appealing a ruling that ordered it to stop storing data from people who don’t have an account with the social network, or face a €250,000 daily fine.

Willem Debeuckelaere, president of the Belgian commission, said last May Facebook's "disrespectful" treatment of users' personal data, without their knowledge, "needs tackling." '

At issue is the consent required for the company’s use of a so-called Datr cookie, which Facebook uses to protect its platform and users’ data against “malicious attacks”.

Facebook's lawyers said the ruling forced it to take the "drastic security measure" of blocking non-Facebook users in Belgium from surfing public pages. This was "the only feasible" measure to comply with the ruling without compromising security, they said.

“The Facebook platform requires protection” because its “1.6 billion users put very personal, emotional information online,” said Dirk van Liedekerke, one of three lawyers pleading for Facebook.

“You can imagine how many people would like to get access to that information” and this “makes Facebook a prime target for hackers” with some “600,000 attempts per day in 2011”.

Yesterday’s appeal concerned only non-Facebook users. A second case is pending that concerns use of cookies for users and non-users alike. – (Bloomberg)