There are very few disclosures that are actionable as such. Some statutes prohibit release of medical information without your consent; others govern what lawyers can disclose. Defamation is a 'disfavored' cause of action: people in America want to believe they can say almost anything about almost anyone in a free country, so they don't like defamation claims. I'm not at all sure that revealing that you were previously married a couple of times is defamation, in particular if it is true. (Truth is almost always a defense to defamation.) You might try seeking an anti-harassment injunction, if you can show that the relative has no legitimate reason for making these disclosures, and his purpose is to harass you.
Answered on Mar 07th, 2017 at 4:59 AM