Watermarks or small changes that encode the user accessing materials, such as small dots on printed material, or hidden metadata on electronic documents. https

Watermarks or small changes that encode the user accessing materials, such as small dots on printed material, or hidden metadata on electronic documents. https://en.wikipedia.org/wiki/Machine_Identification_Code https://en.wikipedia.org/wiki/Machine_Identification_Code This also recently was made public that Xbox did the same with private builds of console software for people releasing youtube videos of unreleased software. https://www.gamerevolution.com/news/469221-how-microsoft-caught-xbox-360-nda-breakers https://www.gamerevolution.com/news/469221-how-microsoft-cau...