Convergence will occur naturally as people become more informed -- and populate their "cognitive model" with factual information about actual risks and effective countermeasures. Of course, Schneier reminded the audience, it's not that simple since the public is exposed to skewed data depending on the agendas of those providing information, whether it's the media reporting sensational stories, politicians looking to secure their own careers, vendors looking to sell their products and so on.

Having an agenda doesn't make someone malicious, but it illustrates the fact that security trade-offs -- what someone is willing to risk vs. invest -- are personal, Schneier said. "Different stakeholders will evaluate security trade-offs differently, and that makes sense," he said.

"Very often security trade-offs are made for nonsecurity reasons," he added, citing as an example news that broke this week that the United States is outsourcing the printing of passports to a company in Thailand. "From a security perspective it's a really dumb idea -- but think of the savings," he quipped.

Following his talk, the standing-room-only crowd peppered Schneier with questions about surveillance cameras ("At best cameras seem to move crime around," he said), electronic voting systems ("Even if there is no manipulation, if there is the perception of, the likelihood of, the chance of, or the belief of manipulation, then the acceptance of the accuracy of the election is suddenly a problem."), global warming and more.

One attendee voiced that he agreed with nearly everything Schneier said -- which the attendee said made him profoundly pessimistic when thinking about the agendas of today's society.

Schneier responded by saying there's cause for optimism: "I'm not a pessimist -- even though I have all the information that I just shared with you -- because in general the system works, the system does tend to converge on reality," he said. Society has a history of managing new risks, getting used to new a technology and normalizing it, he said. But it takes time.

"I tend to be short-term pessimistic and long-term optimistic."

Schneier's most recent book is Beyond Fear: Thinking Sensibly about Security in an Uncertain World.