I'd be interested in knowing if and where it is legal.  I will tell you this, about 2 yrs. ago, a company owed me over $800.  After numerous unreturned phone calls, emails and faxes, one night I was so mad, I sent an email to them and threatened to go to the courthouse in the morning and file Materialmen/Mechanic liens against the subject properties naming their company. It was just a bluff.  The next morning, I was inundated with emails, phone calls and I rec'd a check overnight for full payment. And it cleared.  If it's not legal, it should be.  An attorney can file an attorney's lien on a property he/she performed a title exam on that they weren't paid for.