Christian Hernandez admitted the social networking site had "not done a good job" in educating users on how to use their privacy settings and reduce the amount of available information on them.
However, he highlighted the robustness of the privacy tools availble to Facebook users, saying: "The user has to be in control."
The admission follows calls from US senators this week for Facebook to overturn recent changes to the site that allow users' information to be shared more widely with third-party sites.
Hernandez stated that Facebook, which has around 400m monthly active users, did not plan to become the world's biggest website, saying: "Our aim is not to take over the world. Our mission is to connect the world."
He also joked with the audience that every change the site makes results in picketing outside the Facebook office, adding: "We're getting used to that."
Hernandez told delegates that the site needed to engage more with UK publishers and highlighted new social plug-ins for third-party websites, unveiled at the site's f8 conference in the US last week.
These include a new "Like" button whereby visitors to a site can insert a web page into his or her newsfeed on Facebook with one click.
More from the PPA Conference
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