I think what the parent was getting at is people are bad at evaluating risks whose potential negative consequences won't manifest for decades.
It's true of smoking, and it's very likely true in the case of surveillance. There aren't similar studies demonstrating this for impact of surveillance on the wellbeing of nations over periods of decades because it's totally infeasible.
However, there is a good amount of evidence that it's very dangerous (and you can come to a similar conclusion by reasoning)—so the question should be whether it's worth the risk in the face of uncertainty.
There were such "studies". One result of such is the German refusal of accepting a surveillance state.
Edit: parentheses around studies relevant, I know the difference between a correctly designed controlled study and a historical observation. Point still worth making.
It's true of smoking, and it's very likely true in the case of surveillance. There aren't similar studies demonstrating this for impact of surveillance on the wellbeing of nations over periods of decades because it's totally infeasible.
However, there is a good amount of evidence that it's very dangerous (and you can come to a similar conclusion by reasoning)—so the question should be whether it's worth the risk in the face of uncertainty.