Brian Krebs has done this once or twice, so he's built a collection of resources already making it a lot easier for him.

A simple answer would be there is more to onion sites and 'the dark web' than just the Silk Road.

Read through Kreb's archive, he has screenshots and more info. If I remember correctly one was on the clearnet but required some sort of verification before you got access.

I've been a fan of Krebs for a while. He get's a lot of access and information from other hackers (that were pissed at another hacker) or security analysts. Gotta give him props though, he taught himself a lot, including learning Russian

I think one of his best features is his follow through too. Real good journalistic nose for following a lead.

Credit card data is stolen all the time. Card skimmers, cell phones, cameras, just writing it down while working somewhere, pulled out of compromised email accounts, etc etc the list goes on. Criminals then upload them and sell that data online.