GCHQ and NSA alternatives
The GCHQ and NSA archives aren't open to the public.
On the other hand, archive.org (the wayback machine) is accesible to the public for free (at the moment) and access just needs a browser and not much else. How hard can that be.
Anything more obscure than that and there are a few computer museums, the classic computers mailing list, and so on.
If Cerf had said we need to preserve *knowledge*, the kind of stuff that used to be in the non-fiction section in buildings called libraries, then he'd have had an excellent point.