Such speculation is useless and the (movie's) argument is not logic.
"Such speculation is useless":
a) The goal of knowing truth is survival, but survival depends also on other aspects, and moreover, survival is just possible for a limited amount of years. Therefore, with or without truth, we will end our physical existence at some point.
b) The value of truth of anyone's statement is usually known on the long term. As an old person, I just can tell you that you just know people better, and be more selective about your relationships.
c) The truth about anyone's statement is this: his priority is to survive (according to his perspective of facts), then his second priority is the survival of the group. If you risk that, the probabilities of lying are high.
d) If we would able to know truth from all statements, perhaps we would be extinct, perhaps not, but such alternative implies a parallel reality, which is not physically possible to experience. Why do not think of a world where everything is pink, a world where anybody can traverse walls, or a world where every dream becomes truth the next morning? Such speculation seems far more interesting.
"The argument is not logic":
a) Knowing truth means knowing all truth, and that's not possible.
b) The issue of your question is related to privacy in a nature where privacy does not exist. Well, "aosfqwfaowifnafsdfkasdfaos" don't exist in this nature, so, take your conclusions.
c) The movie deals about a factual impossibility, your question deals about a fact that is real nowadays: personal-level integrated information databases do exist. And that's not ethical (nor legal in some countries, as in France). Why? Again, because it risks survival, of the group and of the individual. The movie is therefore not relevant.
d) If you are worried about survival coming from "external" sources, you are losing your time. From what it seems, we'll be extinct in a couple of centuries, unless we start making war, to compete for earth's administration, which should do more worries.