[DJN]

If something is in the public's interest, it generally makes sense to disclose it to the public.

For example, if a car manufacturer (or bank) makes public claims that their system is secure, yet they use 56-bit DES keys to encrypt data, then I think the public should know.

Your "account number" analogy was off because it's is generally not in the public interest to reveal a private citizen's account number.

However, if an account number (email address or ip address) was being used frequently to commit crime, say in an advance fee fraud, then it makes sense to blow the lid on the said account number. That's what I meant by "in the public interest".