It will be interesting to see how this plays out
From what I have been able to gather, this guy isn't your normal run-of-the-mill wacko. He apparently owns multiple companies, is involved in venture funding, and may even be a former employee of New York Life.
He made an investment with New York Life that didn't live up to promises - like most investments over the last couple of years he probably lost money. He demands that they return the money that he invested. They refuse. He then says that he will say unflattering things about them in a very public way and that millions of people will hear about it unless they return his money (with triple damages, down to the penny).
He was right. Now instead of a drop-in-the-bucket spam campaign, thousands of news websites around the world have picked up the story. My guess is that he was rather careful with his comments and didn't publish anything that wasn't true.
All that has to happen now is for a pre-arrest copy of his website be "leaked" to Wikileaks or similar and every news agency in the world will be linking to it and distributing it further. Since someone has probably cached or copied it, he doesn't even have to do it himself.
According to the FBI, the reason they moved forward is that the amount of money that he demanded was larger than the alleged grievance - not that he had threatened to send a bunch of spam. After all, they couldn't charge him with violating the can-spam act if he hadn't gotten around to sending anything.
It almost seems like he planned it this way, taunting them and daring them to take the bait. Now we will see if they can swallow it, or whether he has caught himself in his own trap.
In the interest of full disclosure, I should mention that I personally have multiple investments with New York Life. My NYL adviser was very clear on the risks involved when I signed up, and I had to sign statements showing that I had read the disclosures. I'm sure that he signed similar paperwork, whether he remembers it or not. He probably doesn't have a leg to stand on as far as getting his money back -- unless he has some incriminating document promising something that should never have been promised.