Depends, much as with the other issue there is the ethical side, and there is the popular demand side.
In my view it would be unethical for fedex to inspect contents of packages outside of legal obligations.
On the other hand the general population might demand Fedex inspect such packages and reject shark fin packages, therefore showing demand for them to do something unethical.
In the other case we were talking about providing a service of overnight shipping, which I wouldnt say is a huge ethical issue.