Spoofing user-agent

[Anonymosity]

I discovered that in Opera 10.61, the user-agent spoofing does not work at all. I tried to set the user-agent in Site Preferences for a particular site to be masked as Firefox and then as Internet Explorer, and found that the user-agent was not affected at all. Opera still identified itself as Opera with the Presto rendering engine. I then tried to change the setting in User Prefs in the Preferences Editor by Script Spoof and that had no effect either. Why include those settings if they have been disabled?

Is there some sort of add-on that one can use in Opera to specify exactly what it should put into its request headers as a user-agent?

UserAgent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X; rv:1.9.2.9) Gecko Firefox/3.6.9

[James]

The truth is, spoofing no longer works... period. Steve Gibson unmasked this little secret some weeks back on Security Now on TWIT. As an aside, dumping one's cookies, trying to prevent cookies, trying to mask one's movements online... all of these attempts actually make us stand out more and identify our machines from millions of others. About all we can do is make sweeping changes to our systems on a relatively regular basis to prevent this identification of our boxes.

UserAgent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.8) Gecko/20100722 Firefox/3.6.8

[Anonymosity]

Actually, it does work, under limited circumstances. It is a bit strange. If I try to set the masking using the button that lists all the host names, pick one or add one, and try to modify it that way, it does not work. If I visit the site and access the setting from the Tools menu, the masking does work, but I have to visit the site first. Since my natural inclination is to change the setting before visiting the site, I was not seeing the results I expected.

UserAgent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X; rv:1.9.2.9) Gecko Firefox/3.6.9