Stopping authors from posting Javascripts/Ads in Posts

Hello !

I remember back in the old days when I used to blog in WordPress.com – one could not post javascripts,ads,etc (i.e – AdSense).

We have a Lot of users {authors} (and growing). From time to time, some of them would post AdSense and/or javascript which might be harmful and/or annoying.

Is there a plugin to strip the post off any javascript ? I search for over an hour (Searched /extend/plugins).

Please advice.

– Regards