Patents, copyrights, trademarks, as well as trade secrets and related rights can be used to exclude free riders. These rights are usually collectively called "intellectual property" or IP. Everyone should know how to cost-effectively protect their own rights.
Field, Thomas G. Jr., "Avoiding Intellectual Property Problems" (2001). Law Faculty Scholarship. 400.
PDF created from the author's home page on the Pierce Law Center website. Includes the notice: "Copyright Franklin Pierce Law Center 2001. All rights reserved."