Generally, a vexatious plaintiff is a plaintiff who files multiple lawsuits with a shaky legal basis on the hopes of getting the defendant to settle for a small cash amount.  Sometimes, vexatious plaintiffs even put a price on the lawsuit, and call it "nuisance value." 

Some states have enacted laws to prevent vexatious plaintiffs from plying their trade.  Unfortunately, those laws only apply to individuals, not corporations.  Too bad, because here's one vexatious plaintiff who has filed over 19,000 frivolous, time-consuming, costly lawsuits.

"...the RIAA has brought 19,000 cases against private individuals. "You have a multi-billion-dollar cartel suing all sorts of people who have no resources whatsoever to withstand these litigations," Beckerman says. His concern is that "due to the adversarial nature of justice, the RIAA will be successful in rewriting copyright law," particularly if the technological community does not resist."

The easiest way to prove groups like the Chamber of Commerce are nothing more than corporate stooges is to ask them to oppose the antics of businesses who abuse the court system.  They won't.