We risk losing all the extra popularity and then some when tons of user’s browsing history becomes compromised.
You also lose 95% of the Web because people don’t want to start (they can install, but won’t run it) a second browser.
You probably have 2-3 browsers on your system, and you know how many you run at the same time.
(I have like 5-6 and I run up to 3-4 at the same time, but I assure you the average FB user does not.)
I said it (when dyates asked about it here: De-anonymization / IP leaking when using the Firefox plugin - #3 by janitor) a long time ago: Tor Browser. But because this issue (and overall security challenges) has been underestimated, the MVP site directed users to FF, with privacy and security consequences that have become obvious to me on Day 1 (when I changed my browser settings manually and tried to see if I could get to the server(s) hosting the PAC file).)
I didn’t look at referrer info from leaky SAFE sites but I imagine that leaky sites (referrers) appear as “localhost” (client) to referred clearweb sites. Still, it doesn’t take much to connect the dots. Anyone who plans to use SAFE for serious anonymity, privacy and security should wait or at least use Tor Browser.