[…] It took way too many years to get those [Feynman Lectures on Physics] lectures online after (you guessed it) a fight over copyrights. However, online the lectures went and now it appears that publisher Perseus is unfortunately using the DMCA to block attempts to make the works accessible via Kindle or EPUB formats.
https://www.techdirt.com/articles/20140304/17500826434/disappointing-dmca-being-used-to-make-feynman-lectures-physics-less-accessible.shtml