I've worked with a giant pile of random embedded boards. Those boards often come with a CD of random Linux bits designated as a "board support package", and more often than not those random Linux bits represent a random snapshot of some subset of RHEL. It seems highly likely that at least some device vendors make the mistake of actually *using* those random Linux bits, and highly likely that at least one of them didn't bother satisfying their GPL obligations. Red Hat Network never comes into play.