[gpm]

For distributing it, making copies of it, and violating contacts, definitely. For using a program already on a computer with no click through contract that you agree to to run it (or other contractual obligation), I'm not aware of any cases.

That they can sue is a non statement, you can sue for anything, but I don't believe it is obviously (or even likely) copyright infringement...

[LocalPCGuy]

To be clear, it would be ChessBase that would be sued, not individual users. And ChessBase would be the one allegedly in violation of "distributing it, making copies of it, and violating contracts". Since their license to use Stockfish seems to be revoked, it seems like it would fall under copyright infringement at that point (although up to the courts to decide, of course).

[gpm]

Certainly, I'm just responding to "So, not like a book, where if you have the physical copy you can generally read it"

As far as I know it is like a book, if you have a copy you can read (execute) it, you just can't make new copies for your customers.

Whether or not that helps ChessBase... well... ya...

[TeMPOraL]

Even if you could execute the code you somehow obtained, but for which you've somehow lost the license, for ChessBase it becomes worthless, as they can no longer distribute - whether sell or give away - anything building up on it.

[dmurray]

They do also have a cloud offering - you pay them to evaluate a chess position on their computer - so I could see the license to use the code being important, though it's separate to their flagship offering of shrinkwrap software.