Comment 14 for bug 244439

Despite the "nasty debian versioning games" (which only exist for nspr and nss nowadays), I bet this doesn't fail on debian. Because I've always be careful that libnspr4.so and friends are symlinks to the versioned libraries. And while the burden was on iceweasel before, the symlinks are now provided by nspr and nss themselves. So to fix this, Ubuntu just needs to "take back" from debian.
As for Ubuntu users, they can certainly install libnspr and libnss from debian, and be happy.

Ben, maybe you should take a look at recent debian packages before speaking.