The reference manual for the D Programming Language (a successor to C and C++ with various high-level ideas) contains a very fascinating clause on the first page of the language description:
Note: all D users agree that by downloading and using D, or reading the D specs, they will explicitly identify any claims to intellectual property rights with a copyright or patent notice in any posted or emailed feedback sent to Digital Mars.
I have the impression that such a clause — which automatically becomes binding for a user merely by reading the documentation and demands something that the user may not even be able to deliver — is a bit absurd. I would be interested in the opinion of the blawgers on this.