Anyone remember this
Basically, the premise is that with the advent of new technologies and instant communication, the world is just not safe anymore. The US government calls for a "Truth Machine" to be invented - a machine that would 100% tell if someone is telling the truth or not. It takes many years of development, but they finally do it. The remainder of the book deals with the massive social changes that come about once everyone is used to telling the truth, all the time.
IIRC, terrorism is mentioned in the book as one of the big reasons why the truth machine is needed. 200 years ago, an insane maniac was very limited in the amount of destruction he could do. Nowadays, one maniac (much less a whole group of them working together) could do a whole lotta damage.
I don't know if a Truth Machine is possible or not, but it sure would be nice to have one, considering the recent events.