I suspect you can just add them so long as you don't have an NDA. It might result in losing them as a customer if they had an expectation of privacy (for exampl

I suspect you can just add them so long as you don't have an NDA. It might result in losing them as a customer if they had an expectation of privacy (for example, if it affected one of their acquisitions) - but that's usually done through an NDA.