Here's the problem:
http://www.businessinsider.com/r-florida-man-gets-nine-years-prison-in-new-jersey-over-global-poison-plot-2015-2
I don't see how your given ricin example applies to the topic at hand. We cannot control what people do with the tools they are given, or have access to. Apples/Oranges.
I infer the stated intention of #OperationDarkNet and enabling an escrow service seems noble and made with honest foresight, to offer a win/win solution to an existing issue. You submitting a Breaking Bad coffee sweetener story - is like asking what's the price of beans in China, i.e. it's non-sequitur and unrelated.
The issue is association; it only takes one bad apple ruins the whole barrel.
If this guy had happened to be using bitUSD and our community was openly supporting dark commerce it is not such a stretch to for a headline-hungry journo/blogger/newsfeed to punch out "Bitshares supports illegal commerce with bitUSD integration in Darknet Markets".
Sure, Bitcoin is used extensively on the dark markets. Method-X is spot-on in his analysis and Bitcoin would never be what is today without drug trafficking.
But you sure don't see the core devs or community saying "Let's publicly support illegal commerce!".
Bottom line is public perception of the dark markets is exactly that - a place where people do things they can't do publicly and legitimately. Do we as community want to associate with that perception?
There is now a way to go after the same demographic with less risk. The medpot community overlaps the dark market community, once medpot is on board organic adoption to other markets won't take long.
Support the legitimate and legal use cases, let the others follow.