From my understanding they only caught up to Ulbricht because of a mistake he or someone else made involving national borders."The hidden Internet isn't hidden and your anonymous activity isn't anonymous," it said. "We know where you are, what you are doing and we will catch you."
Sellers who did it right won't get caught; the site itself was never supposed to have any identifying information about the vendors. These 8, and those who remain to be caught, probably relied on SR's mixer rather than depositing/withdrawing anonymously (by using external mixers, bitcoins bought for cash, or other means that don't tie their identities to their adddresses).
You don't hear a lot in the way of peddling these days. Door-to-door has been transferred into network endpoint to network endpoint. And there is always something very seedy about peddling now. It is always drug peddling, CP peddling, or peddling crack-pot ideas. Not much left for an honest day's work for your average peddler.unraveling the network of drug dealers who made fortunes peddling illicit substances through the site.