You normally can sue a company if that company has subjected itself to U.S. law by conducting business in the U.S. (either in state or federal court) based on subject matter jurisdiction and diversity jurisdiction/in personam jurisdiction. Those phrases are from civil procedure rules in your state. If you are not harmed by this company, you may not be able to prevail over the suit. Further, at some point, the company could show your prior lawsuits are abusive and bad faith (playing devil's advocate here) and could try to have your suit dismissed. Basically, anyone can sue anyone; the issue becomes whether or not the suit itself will continue because jurisdiction has been met, a question of law has been presented or whether it will be dismissed because the initial issues have not been met.