I've been writing long enough that I know some rather popular authors who have been sued over various issues.
In my rather uninformed legal opinion, most of the issues seemed to revolve around people who thought writers were rich, and some cold hard cash could be had by suing them.
First, let me dispel the myth that authors are rich. Very few are wealthy unless you're talking about the 10-20 names that hit the big lists all the time.
In every lawsuit I personally know about, the writer came out with their reputation untarnished, but with their bank accounts significantly lowered because of forking over hard-earned money to an attorney to defend them.
Axis Pro & WriteInsure
Last year, the Authors Guild entered into an arrangement with Axis Pro, the leading media liability insurance underwriter to offer Guild members affordable insurance for their published work.
Whether your writing is freelance, blogging, or book, you can get insurance under WriteInsure for claims of libel, invasion of privacy, copyright or trademark infringement, plagiarism, errors and omissions, etc.
Liability limits begin at 100K/each loss with a 300K limit. You can get higher limits if you need them.
WriteInsure will cover legal expenses for defense and any monetary damages if you lose. Of course, what you want is for legal defense expenses to be covered until the court dismisses the case with a motion for summary judgment.
Interested? Visit The Authors Guild to find out more. You can also see if you qualify for membership in the Guild if you're currently not a member. I highly endorse them.
A professional writer needs a professional advocate, and the Authors Guild provides that.