[w00t]

DPR got caught because he was really exceptionally poor at not posting things "subtly" about the Silk Road, and had multiple fake IDs shipped to his home address at once.

On top of that, Silk Road itself was poorly configured, and leaked it's IP to the FBI( and anyone else looking ).

Perhaps most egregious, though, was that he didn't have his personal systems properly encrypted, and he didn't delete incriminating logs as soon as they were no longer absolutely critical. This meant that, once he got arrested, he didn't have a chance.