Its interesting that Chessbase has a history now of selling engines that have credible allegations against them.
Rybka - though the story on that engine is a bit weird - part of its original build was apparently heavily lifted from Fruit but the final version who knows.
Houdini - accused of being a Stockfish clone
and now Fat Fritz and Fat Fritz 2.
One issue is that Chessbase doesn't develop these engines, Chessbase acts as a publisher really.
The response I got last night from Chessbase:
Fat Fritz 2.0 is not a Stockfish clone. Please have a look at the following articles on our news page where Albert Silver explains the genesis of Fat Fritz 2.0:
en.chessbase.com/post/fat-fritz-2-best-of-both-worldsas well as this interview:
en.chessbase.com/post/interview-with-albert-silver-his-journey-to-fat-fritz-2-0Which I replied quoting the Chessbase site:
* Fat Fritz 2 is an original neural network that is powered by a
modified version of Stockfish. Stockfish is an open-source project
licensed through the GPL v3 with all due rights. The source code of
Stockfish and the modifications for Fat Fritz 2 can be found on
Github.
I think the only way Chessbase will understand this is if they are punished in the pocket book. Take your money elsewhere. If you are EU file a complaint against them.