"A Simple Active Attack Against TCP"
Laurent Joneray, Merit Network Inc., April 24, 1995
The 5th USENIX UNIX Security Symposium.
(Don't know why I didn't remember this earlier, sorry.)
I imagine that is what Checkpoint did.
It contains a full discussion plus some results of trials.
You should be able to find it through http://www.usenix.org/
What you can't stop happening is that things do change, as a result, so
it just becomes a matter of detecting those changes and making an