My company uses Github Copilot. We have a very specific enterprise agreement that states that data does go to Microsoft's servers where it gets processed in an ephemeral environment and wiped after 3 months.

I'm guessing Anthropic has something similar in their agreements. Now, if you have some proof that Anthropic is stealing highly confidential and/or trade secrets, that'd be good to see, but also whomever is throwing that kind of information into an off-premises and non airgapped model is just asking for a data leak.