https://sfconservancy.org/blog/2021/jul/23/tivoization-and-t... https://sfconservancy.org/blog/2021/mar/25/install-gplv2/
"I give you source code, you give me your changes back; we’re even. … That’s my take on GPL version 2 and it’s that simple. … Version 3 extended that in ways that I personally am really uncomfortable with. Namely I give you source code, that means if you use that source code, you can’t use it on your device unless you follow my rules. And to me that’s a violation of everything version 2 stood for. And I understand why the FSF did it, because I know what the FSF wants, but to me it’s not the same license at all. So I was very upset, and made it very clear, and this was months before version 3 was actually published."
Please stop lying about what is "clear". The actual folks using these licenses disagree.
Here is Stallman on GPLv3
"There are several primary areas where version 3 is different from version 2. One is in regard to [T]ivoisation.
...
The Tivo includes some GPL-covered software. …[Y]ou can get the source code for that, as required by the GPL … and once you get the source code, you can modify it, and there are ways to install the modified software in your Tivo and if you do that, it won't run, period. Because, it does a check sum of the software and it verifies that it's a version from them and if it's your version, it won't run at all. So this is what we are forbidding, with the text we have written for GPL version three. It says that the source code they must give you includes whatever signature keys, or codes that are necessary to make your modified version run."
Who is Stallman you ask? The key guy behind GPLv2 (not the SFC BTW).
I expect that Stallman simply did not know the details of what Tivo was doing, or was worried about what they might do in the future. Their actions didn't include preventing you from running modified GPLed software (although that is a scary thing that is definitely possible and currently likely present in modern devices). They only prevented you from running their proprietary software on top of modified GPLed software. Stallman wanted to prevent that scenario with GPLv3, but the wording that finally made it into GPLv3 still allows what Tivo was doing.
https://events19.linuxfoundation.org/wp-content/uploads/2017...