The markets themselves wern't the weak links. I think most of the people that get caught were caught from making silly errors like Ross was. It's not that hard to track the sellers down when you have to go and post the items. You can find fingerprints on packages and narrow down where they're sent from. Then you just stake out the places and wait. Eventually you'll get a catch.
Yes, good old fashion police work will still catch "criminals" , but what happens when you have a market of thousands of small time dealers competing in a thriving market with little assets each to seize? They can make a few examples at a loss but will eventually run out of money and have to focus their attention on the larger criminals.
Some small time dealers who make mistakes will indeed be caught as well, many small dealers that follow a few precautions will be able to thrive and good for them. I will only be selling legal items on openbazzar as I would have to be a complete idiot to be so outspoken and try and sell illegal items. (additionally, I'm not a fan of drugs, and drug users and want no part of that business)
