However, while we wait for most of the web to upgrade, software testers need to know whether a site is vulnerable or not, and evangelists want to push server operators to upgrade their systems.
Therefore Firefox (and other Mozilla products) log information about “potentially vulnerable” servers to the Error consoleusing the message "<site> : server does not support RFC 5746, see CVE-2009-3555".
In the beginning you will receive warnings for many servers. The idea to log this information to the console is experimental, we may disable it if there are too many complaints or if it's causing too much distraction.