You guys aren't following the clues, and the old adage that sometimes the simplist answers are the correct ones.
It's "John Locke", people. That's why they aren't mentioning the name.
That's why that scene between Desmond and him was so important. He wasn't hiding anything. He said his true name.
John Locke.
It's obvious. This show ain't rocket science.
That theory is blowing my mind!!
Please expand on this... How? What? (in case you're serious)
Was John Locke always MIB? But his name was on the manifest and we saw his flashbacks...