Warning about third part JavaScript
This is something every AdSense publisher should be warned about. Some unscrupulous AdSense publishers are inserting their own AdSense ads into JavaScript without knowledge of the webmaster using the script.
There is a thread at WebMasterWorld which describes what happened to on unsuspecting webmaster when he was using an “email to a friend” script on his site when he happened to notice that every now and then an AdSense ad would be displayed instead of what was supposed to be displayed.
This is a big deal because it violates the Google TOS to display two publishers ads on the same page without prior permission from Google. So if you are running any third party scripts on your site you may want to keep an eye on it!
JenSense has a good write up about what happened
