[WKB]

http://support.mozilla.org/en-US/kb/how-to-use-java-if-its-been-blocked

In order to protect you, Firefox has stopped the Java plugin from running automatically because it has a security issue. However, you can still use Java on trusted sites if necessary. We’ll show you how.

U.S. Department of Homeland Security warning
Mozilla Security blog post on this issue

Table of Contents

Activate Java once
Always activate Java for a site

Warning: You should only attempt this on sites you trust.
Activate Java once

When you see the “Click here to activate” message, simply click it to load the Java content normally.

Activate Java

Note: The next time you visit the site or any other that uses Java you will see this message again.

[Matthew10]

I’m not going to disable anything based up U.S. Department of Homeland Security. They are the enemy folks. Do what you want, but trusting HS is about as stupid as sleeping with a cobra in your bed.