Netscape 7.x to 7.2, and possibly other versions, allows remote attackers to spoof arbitrary web sites by injecting content from one window into a target window whose name is known but resides in a different domain, as demonstrated using a pop-up window on a trusted web site, aka the "window injection" vulnerability.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2004-1158
http://www.securityfocus.com/bid/11852
http://secunia.com/secunia_research/2004-13/advisory/
http://secunia.com/multiple_browsers_window_injection_vulnerability_test/