Attention has recently turned to patent assertion entities that are suing vast numbers of customers using patented technologies in their everyday businesses. But, end users were also principal players in some of the main recent patent before the Supreme Court. In Bowman v. Monsanto, Monsanto sued farmers for re-using its patented self-replicating seeds. In Association for Molecular Pathology v. Myriad Genetics, patients and physicians sued to invalidate breast cancer gene patents. And, patients and drug stores repeatedly challenge pay-for-delay agreements between patentees and competitors, claiming they undermine patients’ interests in access to generic drugs. Finally, end users are likely to become even more prevalent in patent litigation, as the 3D printer becomes more popular, making it more likely that an individual or a small business will make an infringing item that will expose them to patent liability.