The fact that most malware comes from the Play Store and not sideloading proves that Google locking down sideloading is about protecting their monopoly over Android app installation, not users.
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Since about 2015 Google has been trying to leverage the popularity Android gained by being open to turn it into an iPhone-like prison. It all started with the branding change where they killed the cute little Android in favor of the corporate G.
Google is actually much worse than Palantir, because their scope and impact are far larger. Can you imagine anyone willingly using a Palantir-branded browser, email service, or web search engine? But their business is exactly the same as Palantir's: spy on you.
Have you noticed that the Gmail search box has become "Ask Gmail"? Do you seriously believe Larry and Sergei don't have their own "Ask Gmail" box with access to waaaay more information?
I guarantee you all the AI companies have internal versions with no guardrails except for who is allowed to access them. Can't have people leaking the information or abusing it in a way where they might get caught. It's too big a temptation, too easy to avoid getting caught, and too easy to explain away as a testing tool if they do get caught.
Such a tool at the NSA was among Snowden's leaks. And now Snowden is stuck living in Russia and it's business as usual at the NSA.
Software, including ML, had already taken over our lives long before LLM chatbots came along. By the time that control becomes blatant it will already be far too late.
The war on general purpose computing is to ensure you and I can't use software to fight back. We've pretty much completely lost that war already. Nearly every one of us carries a portable telescreen everywhere we go. How do you think ICE is finding people to arrest? I'd say deport, but deportation isn't their main tool.