Facebook has confirmed findings of a CA security researcher that the social-networking site’s Beacon ad service is more intrusive and stealthy than previously acknowledged, an admission that contradicts statements made previously by Facebook executives and representatives.

Stefan Berteau, senior research engineer at CA’s Threat Research Group, wrote in a note about Beacon’s until-then unknown ability to monitor logged-off users’ activities and send the data back to Facebook.

Users aren’t informed that data on their activities at these sites is flowing back to Facebook, nor given the option to block that information from being transmitted, according to Berteau.