All I can think of is the vast number of people that quilt - those attorney's would be one busy bunch of people trying to look at every quilt to see if there's an infringement on policy.
My BIL is an attorney I asked him about it tonight and he said unless the company sends a legal notice with each bolt of fabric to the buyer, stating that they have a copyright and need to be notified if someone is going to display it in a show; there really can't say anything. He said about the only time you might get into the gray zone is if you win a large sum of cash you would probably need to notify the manufacturer.
He said that there are a lot of old laws on books out there that have never been amended or updated in years! He said they would have a hard time of them trying to get a judge to hear it in court as they're already overloaded with nonsense