If you read the report about how he was caught you'll find that the reason he was caught was because of bad luck more than anything else, they actually found fake ID's he'd purchased through random searches, the problem is the media are going to report this as if it was a deliberate and cunning move on their part rather than admit they just got lucky when taking down Silkroad.
That's not actually true. He was caught using good old fashion detective work and he fucked up in the beginning when he was setting it up by posting on forums he'd signed up with under his personal g-mail account and using the same usernames etc.