What if we just tried to make the remote accesses apparent to the user,
by making a warning.warn() call in the default implementation that was
deactivated by a setFeature() call.  With a warning, code will continue
to run but the user will at least be aware they're hitting a remote
resource, and can think about it, even if they decide to suppress the
warning.

We should also modify the docs to point this out; it's not likely to
help very much, but it's still worth doing.