This article examines the plagiarism detection service Turnitin.com's recent expansion into international writing assessment technologies. Examining Turnitin's rhetorics of plagiarism alongside scholarship on plagiarism detection illuminates Turnitin's efforts to globalize definitions of and approaches to plagiarism. If successful in advancing their positions on plagiarism, Turnitin's products could be proffered as a global model for writing assessment. The proceedings of a Czech Republic conference partially sponsored by Turnitin demonstrate troubling constructions of the "student plagiarist". They demonstrate, too, a binary model of west and nonwest that stigmatizes nonwestern institutions and students. These findings support an ongoing attention to the global cultural work of corporate plagiarism detection and assessment.