New York, May 20 :A lawsuit against Facebook has been filed in a US court, alleging that the social networking giant may have violated federal privacy laws by scanning private messages, a media report said on Friday.

The lawsuit, certified for class action in Northern California District Court, claims that Facebook follows the practice of scanning and logging URLs sent through the site\'s private messaging system which is in violation of both the Electronic Communications Privacy Act and California Invasion of Privacy Act, technology website The Verge reported.

The plaintiffs claim that Facebook routinely scans those URLs for advertising and other user-targeting data and maintains those records in a searchable form.

However, the social network said that private messages are scanned in bulk and the URL data is anonymised and only used in aggregate form.

Facebook described the records as \"more akin to The New York Times publishing a list of bestselling books...the anonymised and aggregated data is used to indicate the popularity of information\".

Describing the collection of that data as a privacy violation constitutes \"a technical attack on basic elements of computer programming,\" the company argued.

The court records strongly suggest that the company maintains a persistent record of the links sent in private messages.

\"The records that Facebook creates from its usersâ€™ private messages, and which are stored indefinitely, may be put to any use, for any reason, by any Facebook employee, at any time,\" the plaintiffs\' counsel said.

The website\'s practices have changed significantly over time. In 2012, it was revealed that Facebook was increasing a linkâ€™s Like count each time it was sent in a private message, an incident that plaintiffs take as evidence that the data is tied to a user\'s profile.

According to Facebook, the practice was discontinued shortly after it was revealed.

While the social networking site is no longer using private messaging data to boost Like counts, the plaintiffs claimed Facebook hasn\'t stopped collecting URLs from private messages.

Facebook sued in US for scanning private messages