printf() - a function famous for never having been implicated in any complicated security bugs. Oh wait.
No, thanks all the same but I'd rather actually see the code I'm maintaining and not trust that the bits I can't see aren't important.
I like the ASCII control characters, but most of them don't belong in my source code and that includes U+0009 TAB. Use soft tabs, set the continuous integration software to barf on hard tabs in source code, along with mysterious trailing whitespace and similar sins.