Scraper sites may violate copyright law. Even taking content from an open content site can be a copyright violation, if done in a way which does not respect the license. For instance, the GNU Free Documentation License (GFDL)[15] and Creative Commons ShareAlike (CC-BY-SA)[16] licenses used on Wikipedia[17] require that a republisher of Wikipedia inform its readers of the conditions on these licenses, and give credit to the original author.[original research?]