Yup. This is almost Shakespearean in its tragic nature, and unfortunately an all too familiar circumstance.
Short story - a guy running for local office sees an online comment he deems over the line. He sets about on a legal quest to unmask the nom de plum of the poster.
Four years and $35,000 later he has the name. And probably not much else to show for it.
http://www.theverge.com/2015/11/23/9772824/commenter-defamation-lawsuit-identity-revealed