That was Tibanne's (Mt Gox's owner) CEO, Mark Karpeles speaking. It's part of an article titled Bitcoin exchanges offer anti- money-laundering aid
Just in case you didn't know, Silk Road is the name of a tor's hidden service
that anonymously sells illegal drugs using bitcoins.
Though I never purchased illegal drugs and probably never will, that announcement disappointed me. What's the point of having an anonymous p2p currency if the money trail in and out of the system will be tracked by the intermediaries? They might as well have registered their exchange in Fort Meade instead of Japan.
On the technical side, however, I don't see how's this feasible. The drug dealer can simply send his new funds to another wallet daily and change its address whenever he sells some coins on the exchange. If I understand the system correctly, this will render him indistinguishable from any other normal Mt Gox trader.