Attached are 2 rulesets for enforcing YouTube Safety mode. The zip files contain the ruleset, a custom blockpage and a README describing the installation steps. v4 is an advanced version of a simpler v2 ruleset that I originally developed based on a request from another SE. The nice thing about the v4 ruleset is that it gracefully handles situations where cookies are blocked. The ruleset would be much simpler without these features, but they do show off some of the cool features of MWG7 that newer users may not have been exposed to previously.
The simpler version (v2) looks like this:
Message was edited by: jebeling on 6/28/11 5:55:09 PM CDT