There are times FireFox presents a confirmation dialog, telling you that you are about to log in to a site that does not requires authentication. The exact text of this dialog is:
You are about to log in to the site “somesite.com” the the username “someuser”, but the web site does not require authentication. This may be an attempt to trick you. Is “somesite.com” the site you want to visit.
And here is how the dialog looks like:
By showing this dialog FireFox is trying to protect you from cases in which someone would like to trick you to go to a different domain. For example, take a look at the following url:
http://www.mybank.com:password@example.com/badsite
The first part of the url is: “www.mybank.com:password”, is not a domain, but actually the username/password used to log to the domain: example.com. FireFox showing this dialog in order to get your attention and decide if you are sure you would like to proceed to the domain.
However, if this dialog is annoying you, you can easily remove it. First, write on FireFox url: “about:config”. This will take you to FireFox advanced configuration. This configuration contains a long list of keys and values. In order to cancel the configuration dialog you have to add a new value by right clicking on the list and selecting: new—> Integer from the popup menu:
On the popup that will show enter the following value: “network.http.phishy-userpass-length”
The press “OK” and enter the value: 255
That’s it. The confirmation dialog should never bother you again.