Another cool thing, from a security perspective, is that there is actually a tool (Safe Haskell[1]) that makes it easy to disallow unsafe behavior and operate a

Another cool thing, from a security perspective, is that there is actually a tool (Safe Haskell[1]) that makes it easy to disallow unsafe behavior and operate a whitelist of trusted modules. So not only is unsafePerformIO well-named, it's also trivial to restrict its usage. [1]: http://www.haskell.org/ghc/docs/7.4.1/html/users_guide/safe-haskell.html http://www.haskell.org/ghc/docs/7.4.1/html/users_guide/safe-...