There certainly is. As of a couple of years ago IBM's 9.0.0.0/8 network was only used for their intranet and not routed outside. I believe several legacy /8's are in the same boat.
IIRC, HP is still sitting on three /8 networks - one from HP, Compaq, and DEC.
HP has two /8 blocks. Many people who at one point owned Class A blocks have given them back over the years. What's crazy, though is that the US Department of Defense still owns eleven /8 blocks.