Okay, sometimes (often) lawsuits just reach a point of absurdity.
I'm currently reading a suit that arose out of the building of the Memphis City Hall in the 1960s. Apparently there was some sort of problem with the marble! So...
The supplier of the marble sued the subcontractor in charge of installing the marble, the general contractor, the City, their supplier, and the insurance company for the job
the subcontractor counter-sued the supplier, sued the general contractor, the insurance company, the city, AND the architect
the general contractor counter-sued the marble supplier and the subcontractor
Confused? Yeah, so am I. And the court allowed all of these claims to go forward in one action. so currently, the parties to the action are: the general contractor, the subcontractor, the insurance company, the city, the marble supplier, the marble supplier's supplier, and the architect--most of whom have all sued each other. Awesome.