I agree completely. Except for one thing: "Already convicted felon or not" makes it sound as if being convicted of felony A makes it easier to handle being accused of felony B. But the opposite is the case.

Lamo could easily have been looking at a scenario where he got far worse punishment than the actual perp. Getting a conviction against a known felon is so, so easy. It's not inconceivable that he would have ended up taking the fall. Just because it happens in spy novels doesn't mean it can't happen.

As for the ethics of turning Manning over to the tender mercies of the US Government: no matter what you may think of the ethics of commiting the particular crime that Manning is accused of, there are limits to how far down the cliff you should follow a suicidal person. When you get a cold call from someone you do not know to tell you about some serious Federal crimes, there are several possibilities. One is that the caller is the real thing. Another, far more likely, is that he's mentally ill or trying to punk or scam you. Yet another is that he's a government agent trying to entrap you. But one thing is for sure: there is nothing that you, the world, or the "hacker" community will lose by turning this guy in. He's obviously an order of magnitude too indiscreet to be a good spy, he's going to succeed in getting himself caught any second now, and the only question is whether you're going down with him.