Krebs is really well connected to the underworld, plenty of people pass him information confidentally, just like any other journalist. He also understands this

Krebs is really well connected to the underworld, plenty of people pass him information confidentally, just like any other journalist. He also understands this field far better than most people, so although he probably did find them "easily", it probably wasn't "on his own" and it almost certainly wouldn't have been anywhere near as easy for you or me to do it.