Although most people will always want to keep their RSS feed running, you may have a reason for wanting it shut down. Many people, for example, think they are running a private blog, yet they still have their RSS feed pumping out the content of the site to whomever wants to read it.
The Disable RSS plugin will shut your feed down for you. (Note: This plugin is a little old, but it worked for me. Another “disable RSS” plugin I tried that was much more recent didn’t work.)
Featured Plugin - WordPress Wiki Plugin
Photo: Aged Sorry We’re Closed from BigStock