Good news, everyone: You don't have to safely eject your USB drives before playing Delta Force, despite what the game might have told you earlier. In a message to PC Gamer, developer Team Jade clarified that the original post was just a "translation error," and that USB drives are fine—it's what you put on them that could get you banned.
"USB drives are absolutely fine!" said a Team Jade spokesperson, so long as you don't use "USB devices that enable certain macros, scripts etc" that could interfere with the game or give you access to certain advantages. So don't run cheats off a thumbstick, basically, and you'll be fine. The list of banned tech has been updated to read "Cheating USB tools" now, rather than "USB drives."
Which makes a lot more sense than the original list of banned tech Delta Force originally put up, which featured a lot of stuff you'd expect—don't use Cheat Engine, or Speed Wizard, or frame-capture software that the game might mistake for an aimbot—but also seemed to lay down a zero-tolerance ban on "USB drives" of any kind. Given how many of us have external hard drives and thumbsticks jammed into our machines at all times, it seemed an inexplicable and draconian ban.