SOPA Blackout for WordPress plugin by sgerrand allows you to easily show your support on SOPA Blackout Day on your blog.
SOPA Blackout website: http://sopablackout.org/
Plugin info: https://github.com/sgerrand/sopa-blackout-for-wordpress
Download plugin: http://wordpress.org/extend/plugins/sopa-blackout-plugin-for-wordpress/