Re:Man sued for $30K over $40 printer he sold on Craigslist
by tacon on Monday June 06, 2016 @03:45PM
(#11849720)
It's usually called vexatious litigation, and many jurisdictions have list of vexatious litigants, whose filings go through a special judicial review before being accepted into the system:
https://en.wikipedia.org/wiki/Vexatious_litigation