Ad Blocking shield free
You work hard at making sure your site provides quality content, and all you ask in return is for visitors to your site to be exposed to the ads, so if one catches their eye, they can click on it. It's a very fair trade, but there are those that want to cheat you out of any income potential while still taking your resources. We call that stealing.

This script catches people who are using plug-ins, add-ons or other software to block Google AdSense, and replaces the page with a message that the software has been detected.

Copy the code and paste it within the HTML of the pages you want to shield against ad blocking software. 

Ad Block Fence
Ad Block Plus demonstrated their true colors by specifically disabling this script, thereby denying site owners' control over their own sites. Since FireFox actively endorses Ad Block Plus's content theft, I personally, block FireFox users except those using IE Tab. I encourage others to do the same. So far it has actually improved my revenues. This script still blocks other ad block software users. 
FireFox Block (PHP)
Rename "article.php", Create a new "article.php" with the code provided below, changing the line noted to include the name of the original, but now renamed, article.php script. Blocks FireFox users from viewing articles. Should be directed to a page explaining FireFox's active endorsement of content theft. See http://jacklewis.net/weblog/firefoxbanned.html for an example.

  

The handiest way to put it in your AD article directory is to add it to your header template, but be careful, unless the script detects the presence of Google AdSense on the page, it will send you to the alternate URL, so, since Admin pages use the same header, you'll need Google AdSense ads on your Admin pages.