As the first wildly successful mobile game, it's an avatar for the way our understanding of what's private and what's personal has collapsed in the past decade. It's not the only mobile game that's sucked away intimate information, and it's not the worst offender, but it was the first global hit. It was a Trojan horse — the first colorful, fun, utterly unthreatening game that was downloaded onto a billion phones, and the start of a decade of downloading free apps without having any real idea what they were getting from us.
Something as vague and banal-sounding as "gameplay data" is not as obviously salacious as the types of personal data collection we know we should be scandalized by. Nobody's getting your Social Security number from Angry Birds. Nobody's getting your private messages.
...
But people should be worried. The intricacies of gameplay data can tell you a lot about what makes people tick, and what's going on with them — studies have shown that you play games differently when you're depressed, or dieting. "Nobody gets too upset about games," Nieborg says. "But the underlying technology is really powerful. These people are really pushing the technology to the limits where the potential for abuse is massive."
Full article:
https://www.vox.com/explainers/2019/5/7/18273355/angry-birds-phone-games-data-collection-candy-crush
There's been more and more talk about privacy, and I feel like I've seen some pop-ups about telemetry data even in console games from big publishers. It's also interesting that the author explicitly calls out the "it's just gameplay data" argument.