There is a thread at WebmasterWorld that was created on June 5th reporting that AdSense ads are generating onsite JavaScript errors.
There are dozen of reports in the thread that these Google ads are causing this unwanted errors.
A debugger tool reports that there is a missing ';' in the AdSense code. It was then reportedly fixed at 7pm the same day. However, there are more lingering reports of these errors either on https pages or 403 pages.
Forum discussion at WebmasterWorld and Google Groups.
