To a degree these worried companies seem to be overreacting:<p>* Disgruntled insiders always have been a security threat, and usually the biggest threat.<p>* If the seller is operating on open markets, even anonymously, the company has much more visibility into what's happening than before, when the transactions were more private (I assume). The markets must have sufficient liquidity (i.e., buyers) for the seller to succeed, so I would guess that only reasonably well-known darknet markets would be used. Just monitor those markets and you know what is being sold and in many cases can narrow down who the seller is or even catch them and the buyer.<p>* Fear of a sociopathic 'lone wolf' is often exaggerated. Consider the similar reaction to terrorist attacks: People think, 'anyone could buy a gun and shoot up a crowded place', but that's not how it works. Physically, anyone could do it - anyone could drive their car into a crowd, an opportunity that arises billions of times per day - but people don't do it. The evidence is overwhelming: Human behavior is much safer than we fear.<p>* I suspect some is an overreaction to an unfamiliar new tech with a scary name: The Darknet.