"Doxing" is a neologism, describing the act of publishing identifying information (or 'docs'), typically personal identifying information, on the internet. It's usually done with the intent to bring indirect harm against one individual, and is typically associated with "hacktivism" or vigilantism, but is sometimes an isolated individual act (retaliation against an unfaithful spouse, for example).
Doxing is illegal, per state and common law, but not federally, as far as I know. It also typically violates Terms of Service agreements for many types of internet services.
However, I'm interested to know what would constitute "doxing" as it's defined in case law or state laws, generally. What information would be legal or illegal to publish publicly?
Some information is publicly available. Full names, names of spouses or other family members' addresses and home phone numbers are published in phone books and on voter registration databases I can't understand how it would be illegal to essentially "re-publish" that information, but obviously information not publicly available like social security numbers or cell phone numbers.
What constitutes "doxing", as defined in the law?