I never thought I'd find myself doing this, but on this one issue, I actually agree with AL. If you play in Open, equipping a cargo ship as a blockade runner makes a lot of sense, and you sacrifice almost nothing to do so, at most one light year of jump range, before any FSD modifications. Shields, even "navigation" ones, are just common sense, and everything else involves fully utilizing every module location on your ship.
For losing a single light year if jump range, which might cost you, at most, 45 seconds of time on a trip, you end up with a ship that can soak up a lot of damage. It's the difference between flying an armored car, and a cardboard box.
That having been said, I think anyone in Open who sees a cardboard box and thinks "free kill," rather than, "someone in need of an education," is being a jerk. Here's hoping the upcoming C&P changes reduces the amount of jerkish behavior, or at least gives potential jerks a momentary pause.