It's All Relative: Guilt and Innocence

It's a bit scary how broad and encompassing US federal law can be. As Ilya Somin points out - if you're in the US or travel to the US, you're probably already a federal criminal (Volokh). And then let's say you end up committing a crime (or 'just' get accused of one), as far as forensics goes? I'm betting you didn't realize how frighteningly subjective and fallible it is (Popular Mechanics).