just block their internet access at the router, right?
You can do it but it just might make no difference
If your matter devices are connected to ha (matter server) it will deligate the device attestation from the cloud to “your” device. So you might disable internet for HA - but then you are probably not able to commission any new matter device (which requires to connect to the “mother ship” DCL to allow using “your” device).
You might modify the the matter server/controller (probably loosing certification - whatever difference it makes) like described in this thread
TL;DR You don’t own matter - matter owns you
I don’t see any reason why the rug pull that futurehome did shouldn’t have worked the exact way if it would have been a matter device.
Futurehome (what a name!)
Futurehome proves why it's more important than ever to take back control of your smart home Futurehome smart hub owners must pay new $117 subscription or lose access - Ars Technica
AFAIK the matter specification does not prohibit such actions
makes me question what happens when the manufacturer goes out of business, or simply decides to drop support for those products.
Good question! What happens with certificates that expire after X years? EOL and they stop working or only have limited functions then? Would it even possible for others (like CSA) to re-issue valid certificates if a bad actor with the private key does not cooperate or is just gone
From great power comes great responsibility.…
But do I actually want to have others (more) power over “my” device then myself