Just read this today:

"RSA, one of the leading global manufacturers of cryptographic solutions, has apparently fallen prey to an attack in which data was stolen from its servers.
[...]"
[ http://www.h-online.com/security/new...s-1210393.html ]

and
"According to Tor developer Jacob Appelbaum and a blog posting by the Mozilla Foundation, the Comodo SSL Certification Authority may have been compromised. As a consequence, criminals apparently obtained nine certificates for web sites that already existed, including addons.mozilla.org.
[...]
[ http://www.h-online.com/security/new...e-1213358.html ]

Are these relevant for N900?

Patches for various software on other platofrms have been released, I don't know specifics about the certificates on N900 work, if it is embedded in the browser or if there's some common shared ones.

More info is here from Comodo: http://www.comodo.com/Comodo-Fraud-I...011-03-23.html