CONSOLE MESSAGE: PASS: Exception thrown successfully. The scenario for this test is that you have an iframe with content from a foreign domain. In that foreign content is an iframe which loads a data: URL. This tests that the data: URL loaded iframe does not have access to the main frame using top.document. Pass: Cross frame access from a data: URL on a different domain was denied. -------- Frame: 'aFrame' -------- Inner iframe on a foreign domain. -------- Frame: '-->' -------- Inner-inner iframe. This iframe (which is data: URL and whose parent is on a foreign domain) is the frame attempting to access the main frame. It should not have access to it.