[This is hypothetical and about no one in particular. Revealing the identify of a federal informant can in some cases be prosecuted as a crime. I would never reveal the identity of an informant. This post is for informational purposes only.]
Imagine you're hungry for attention. Perhaps you didn't get much attention growing up and have serious daddy issue.
The best way to get attention is to convince people your life is in danger. There is nothing quite like a damsel (or dashing man, as this post could apply to men or women) in distress.
You grew up in a SJW culture where words have no meaning. If someone posts something you don't like, they are stalking you.
If someone writes about you and you go to that person's Twitter page to read it (because he doesn't reach out to you), he's harassing you. Forget that this "harasser" never wrote anything to you or even contacted you. Words mean whatever your crybaby gender studies course says they mean.
You grow up in a culture without consequences. Thus, you think nothing of sending yourself a few death threats.
The media and everyone else takes the bait. You're a big star who is finally getting that attention you so richly craved.
Enter the Feds.
Then the Feds come knocking. You foolishly believe that talking to an agent with the Federal Bureau of Investigations is like talking to a gender studies professor. Tell them what you feel and they will blindly accept it. Feels > Law.
Since words have no meaning, you tell these agents you were threatened. (Hey, maybe you or a friend of yours sent the email. But words mean whatever you want them to. You did feel threatened by that fake email, after all, right?)
As it turns out, the Feds don't like being lied to. Lying to a federal agent is a federal crime, in fact. It's called obstruction of justice and it's a felony.
Snitches get hugs and kisses.
The Feds know that prosecutions are political. If you've been given the royal treatment by the media, perhaps the Feds might not want to prosecute you. Like other government agencies, the Feds are sensitive to public relations.
Some tight-asses (no one has tighter buttholes than Federal agents; do not ever lie to these people or even talk to them unless you have an attorney present) say to you:
"Hey, you're a felon. You have a choice - go to prison or be a confidential informant."
The Feds give you an idea. Go find some white knights to help you run Ops. Hack a few sites. You know, the usual.
This is nothing to you. You're an SJW and you don't care about anyone but yourself.
You enlist some hapless white knights to help you.
You avoid prison time and now the FBI has a whole bunch of people they can indict for violations of computer crime statutes. (Or the Feds can turn these white knights into snitches.)
That is how a hoaxer becomes an informant.
This is, of course, 100% hypothetical.