"We have a lot of data," said Tim Campos, Facebook's chief information officer. It was an understatement; Facebook has unprecedented scores of it.

Mr. Campos and Joe Sullivan, the company's chief security officer, discussed how the company balances leveraging this data for advertising and keeping it secure at Ad Age's Data Conference today. "We have very personal information," Mr. Campos said. "And therefore, it's our responsibility to be good stewards of it." That means the company uses its data strategically, not comprehensively, he added.

That said, the two acknowledged that the company made "mistakes," including its much-publicized user experiment.

After the session, Mr. Campos detailed ways marketers can layer in their own information, such as customer relationship management data, with Facebook's demographic arsenal.

Mr. Sullivan also spoke about the company's emphasis on preventing marketer data it absorbs from co-mingling with other advertiser's data. He stressed the novelty of Facebook's entire data artifice. "It's important to remember the internet is a new world," he said on stage. "When Facebook came along, people weren't accustomed to putting their real name online."