I know someone who was declared a vexacious litigant in California. She can no longer file suits. (From wikipedia: Vexatious litigation is legal action which is brought, regardless of its merits, solely to harass or subdue an adversary. It may take the form of a primary frivolous lawsuit or may be the repetitive, burdensome, and unwarranted filing of meritless motions in a matter which is otherwise a meritorious cause of action.)
Some countries have vexacious litigation laws, but apparently the US doesn't.