According to a study from researchers at Carnegie Mellon University, which followed the privacy practices of 5,076 Facebook users over the course of six years, Facebook succeeded in reversing users’ inclination to avoid public disclosure over time. And even as some sought to keep personal data private from strangers by limiting what was available on their profiles, they increased what they shared with friends throughout the years.

The finding “highlights the power of the environment in affecting individual choices,” wrote the study’s authors, Fred Stutzman, Ralph Gross and Alessandro Acquisti. “The entity that controls the structure (in this case, Facebook), ultimately remains able to affect how actors make choices in that environment.”

“As Facebook’s membership grew, and as the site increased the variety of information that could be shared, users in turn became more cautious about what they displayed to unknown individuals, the study found. Between 2005 and 2009, Facebook users in the study exhibited ‘increasingly privacy-seeking behavior’ and gradually limited what information could be seen by strangers. They grew more protective of all types of personal data, from their interests and favorite books to their birth dates and hometowns,” writes The Huffington Post.

But then between 2009 and 2010, “something surprising happened,” notes the article. People became more open with their personal data. “…users’ tendency to share their interests; favorite music, books and movies; hometown and high school decreased steadily until 2009. In 2011, when the Carnegie Mellon team gathered its final set of data, the cohort, which had seemed on a steady march toward sharing less with strangers, was still sharing details with non-friends on their network.”

Why the uptick? “…they concluded the reversal was, ‘with high probability,’ caused by an update to the social network’s privacy controls in December 2009 and the launch of Community Pages and Connected Profiles in April 2010, which made some previously private information about a user’s interests more widely visible,” explains the article.

According to the findings, providing more detail to users about privacy may not be the answer. “They argue, perhaps counterintuitively, that elaborate privacy options might even be part of the problem. Enabling users to choose which specific group of peers — such as ‘friends’ or ‘friends of friends’ — can view their posts can result in a ‘misdirection of users’ attention’ and has ‘been linked to increases in disclosures of sensitive information to strangers,’ such as third-party apps or Facebook itself, the researchers wrote. However, they don’t offer a clear alternative to Facebook’s current approach.”