[Haskell-cafe] Safely reading RemoteRefs?

I notice I'm able to retrieve haskell variables after a :r in ghci: :m + Data.Binary :m + GHCi.RemoteTypes

encodeFile "/tmp/foo" =<< mkRemoteRef "hello!"

(:reload)

putStrLn =<< localRef =<< decodeFile "/tmp/foo"

"hello!" Is this safe? It works correctly in the common case but are there things I need to be careful of? In the string case it's not too interesting but it would be great to e.g. retrieve the pid of a running process. Tom