Yeah, that prediction market player/trader/gambler who manipulated a weather sensor was in the news a few months ago
https://finance.yahoo.com/markets/crypto/articles/trader-manipulates-city-weather-sensor-165804921.html, and it became a serious concern because airline dispatchers, grid operators, farmers, etc. make decisions based on weather forecasts, like what was posted by MIT here
https://www.technologyreview.com/2026/07/17/1140622/weather-data-sabotage.
And again, a quote from someone who operates a casino.
[...]
The casino games are here to entertain you, not to give you money. Imagine if the core business would be giving money, how much sense would that make? Grin As soon as you switch your mindset and you're completely aware that the core business of that slot game is to entertain you, not to make you rich, you will stop caring about these things.
[...]
Like @ryzaadit said, gamblers may be aware of the game being verifiable and stuff, but sometimes gamblers just want to play to get entertained and test their luck in a simple way. How many times have you played provably fair games, and how many times have you verified the results? Maybe it doesn't matter anymore after you have played in online casinos for some years. You know it's rigged, you just don't know how to prove it, you still keep playing, and hoping you get a share from people who get rigged by the system.

People bet on everything, especially after prediction market platforms like Polymarket exist. For me, it's okay, because it also means more ways to get entertained for people who see gambling as entertainment. More ways to make money for people who know the edges. More ways to lose money for people who only rely on luck to get more money.
But there's one market I don't like on prediction markets. It is a bet on wars that happen in specific countries, like "[Country A] attacks [Country B] before [date]." I mean, it's still legal, but come on, you are betting on humanity. You try to make money from the deaths of innocent people? Please, just don't do that.