“I can legally talk about how I did this to a certain degree, and if someone else wants to do this, they can open source it if they want to.”
Echelon pushed firmware that bricks offline functionality and forces subscriptions for features that used to work without internet. Developer Ricky Witherspoon cracked it and won a bounty for doing so. But the DMCA means he can’t release the fix. You can own the hardware, you can prove the company is screwing you, you can build the solution. You just can’t share it. This is what “you will own nothing” looks like in practice.