The only way to ensure privacy is for the data to never leave the user, rather than trusting OpenAI to keep the user's data confidential once it is in their hands.
[1] "Samsung Exposed for Leaking Chip Secrets via ChatGPT! Korean Media Shouts that Data Was 'Transferred Unaltered' to the U.S., SoftBank Has Banned Employees from Using It," Zhihu Column. https://zhuanlan.zhihu.com/p/618865445 (accessed May 09, 2023).