You’re absolutely right, I was being unrealistically conservative. In reality that many workers would almost certainly unionize and average labor costs could easily be $250-$300 a day or more.
Viewing a public tweet is not trespassing - its the point of the entire platform. US vs Jones determined that installing a tracker on a private vehicle is trespassing.
As a tax payer, I would prefer my tax dollars are used as efficiently as possible - so if the alternative is to hire human police officers to manually search twitter and create reports then I would oppose that in favor of automated technology. I don't think the technology is the debate here, it simply enables us as humans to be more efficient. The decision to surveil is the debate here, and I can see it both ways. Do I think the police should be aware of a large gathering (regardless of purpose) in their cities? Yes, I think that's prudent for a variety of public safety reasons. Do I want this done in a way that does not interfere with protests or have a chilling effect? Yes, absolutely.
Aren’t the tweets ingested by Dataminr public? I agree this would be problematic if they were using private data, but using data available to anyone on the platform feels like fair game.