You choose which files to use in Poly, we don't scan your hard drive either.

I don't know about the other services, but Dropbox _does_ read your files. https://help.dropbox.com/security/privacy-policy-faq

> We may build models that identify keywords and topics from a given document. These models may be trained on your documents and metadata, and power features within Dropbox such as improved search relevance, auto-sorting and organization features, and document summaries.

That's the thing. I'm already tied into GDrive, Dropbox, OneDrive, etc. all which have LLMs hooked up to them in some form or other. I'll gladly just wait until those catch up and I'll avoid the switching costs. You're all using the same LLMs under the hood anyway.