This article feels pretty disingenuous to me.
It glosses over the fact that this is surveillance on computers that the school owns. This isn't them spying on kids personal laptops or phones. This is them exercising reasonable and appropriate oversight of school equipment.
This is the same as complaining that my job puts a filter on my work computer that lets them know if I'm googling porn at work. You can cry big brother all you want, but I think most people are fine with the idea that the corporation I work for has a reasonable case for putting monitoring software on the computer they gave me.
The article also makes the point that, while the companies claim they've stopped many school shootings before they've happened, you can't prove they would have happened without intervention.
And sure. That's technically true. But the article then goes on to treat that assertion as if it's proof that the product is worthless and has never prevented a school shooting, and that's just bad logic.
It's like saying that your alarm clock has woken you up 100 days in a row, and then being like, "well, there's no proof that you wouldn't have woken up on time anyway, even if the alarm wasn't there." Yeah, sure. You can't prove a negative. Maybe I would usually wake up without it. I've got a pretty good sleep schedule after all. But the idea that all 100 are false positives seems a little asinine, no? We don't think it was effective even once?