are you giving some personal info away?
JavaScript vulnerabilities in Opera might allow hackers to access user"s cookies and other potentially sensitive files. Veteran bug hunter Georgi Guninski has discovered that versions of the Web browser on both Windows and Linux might allow the executive of script code across domains. This means it"s possible for a hacker to set up malicious script code on a Web page, which when executed by Opera, allow access to the cookie-based authentication credentials of another Web site.
In the meantime Opera advises users to consider disabling JavaScript execution and enabling the "use cookies to trace password protected documents" option, which addresses the most troubling aspect of the problem