Facebook has hit back at recent claims that it had been targeting emotionally vulnerable teenagers for advertising purposes. The social media giant said an article in The Australian newspaper about a leaked research document was "misleading."

The leaked paper, reportedly written by Facebook executives David Fernandez and Andy Sinn, showed how Facebook could monitor photos and posts from users aged 14 years and older who may be feeling "stressed," "defeated," "anxious," "nervous," "stupid," "overwhelmed," "silly," "useless," or a "failure."

The Australian writes that the report, which only covered Facebook users in Australia and New Zealand, was seen by marketers working for major Australian banks. It also explained that Facebook could determine how different users felt at various times of the week, with teenagers supposedly "building confidence" during the early part of the week, and wanting to "broadcast achievements" at the weekend.

But Facebook denies its young users' privacy was violated. "Facebook does not offer tools to target people based on their emotional state," it said. "The analysis done by an Australian researcher was intended to help marketers understand how people express themselves on Facebook. It was never used to target ads and was based on data that was anonymous and aggregated."

The company did admit, however, that the research didn't adhere to established guidelines. The BBC reports that disciplinary action may be taken over the document, pending an investigation into the research.

"Facebook has an established process to review the research we perform. This research did not follow that process, and we are reviewing the details to correct the oversight," added the company.

Back in 2014, Facebook faced outrage after it had emerged the firm carried out a psychology experiment on nearly 700,000 users without their knowledge. The 2012 tests involved it manipulating news feeds to control which emotional expressions users were exposed to.