DRM History: It‘s Older Than You Think http://tedium.co/2017/08/24/drm-history-intertrust-contentguard/

MAME devs are cracking open arcade chips to get around DRM | Ars Technica https://arstechnica.com/gaming/2017/07/mame-devs-are-cracking-open-arcade-chips-to-get-around-drm/