A legal hole in the Creative Commons 2.0 license has allowed "copyleft trolls" to exploit users of CC licensed material. Copyleft trolls post images with an outdated CC 2.0 license, then sues people who reuse the images. CC 2.0 license is automatically terminated if proper attribution is not used, changing the license to a standard copyright. Subsequent licenses have closed this loophole.
With so many places to search for OER, it can be difficult to know where to start. OER repositories at a glance offers a comparison of collections and tools to help make searching less daunting.
On January 1, 2022 works from 1926 and 400,000 sound recordings from before 1923 entered the U.S. public domain, which means they are all free to share, copy and modify. Association for Recorded Sound Collections selected Ten Notable Pre-1923 Recordings to explore from the newly released 400,000 recordings.