Even though it stops folks with updated browsers from accessing your site?
Firefox cannot guarantee the safety of your data on www.backblaze.com because it uses SSLv3, a broken security protocol. Advanced info: ssl_error_no_cypher_overlap
Firefox 35, rc4 disabled
As far as I understood you should not (especially not only) use rc4. https://en.wikipedia.org/wiki/RC4 even cloudflare is trying to get used of rc4. https://blog.cloudflare.com/killing-rc4/
> Fast-forward to 2013 and attacks on RC4 have been demonstrated; that makes the preference for RC4 problematic.