[suresk]

Anyone signing an NDA without knowing what it is the NDA covers is needlessly incurring legal liabilities. I would never sign an NDA unless I knew what it was covering AND it was properly scoped (most NDAs tend to be too broad).

Even then, there has to be a really good reason for doing so - everything you agree to is something you have to keep track of and make sure you don't accidentally break at some point in the future.