Do not accept the premise of assholes.
I hope we can get the EU to fund a truly open Android Fork. Maybe under some organisation similar to NL Labs.
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Furthermore, the need for a trustworthy binary to be auditable to a certain hash or something would make banning this a simple task if Google would want to go that route.
How are things in the EU on whether it's legal to buy a SIM card without showing ID?
The task, therefore, is to convince enough politicians to establish an independent unit that can address this issue without direct political influence.
Fund the unit with enough money so that it can take care of the cybersecurity and sovereignty of all citizens.
A side effect of this would hopefully be that these politicians would then be digitally literate enough to recognize nonsense such as chat control as such and reject it outright. I hope that most politicians would not really want such omnipotent surveillance tools if they could truly grasp their scope.