> some of them would have been caught, and it would've been exposed as a hamfisted and shambolic scandal.

Isn't that the same thing that happened here? It's a news story because they got caught. There is apparently already a law against this sort of tampering and it makes sense to have that law.

> Now, because of prediction markets, the "attack surface" for interfering with scientific data collection is much larger and more fine-grained.

Oil and tobacco companies are the canonical examples because they're huge and contemptible, but the incentives scale all the way down. A small industrial plant is only allowed to use river water for cooling as long as the temperature isn't too high, they now have the incentive to cause the reading to be lower. The local school doesn't have A/C and therefore cancels class whenever the outside temperature is above some threshold, what happens when the kids figure out that the temperature sensor they use is in a public place?

You can make messing with the sensor illegal to apply a disincentive to counter the incentive but that doesn't mean the incentive wasn't always there to begin with.