I kinda thought the same thing when I read this. I guess the fraud was that they intentionally went to great lengths to make it look like individuals were buying the tickets instead of a single company.
Pretending to be someone else to gain profit, is identity fraud regardless of if you stole a real persons identity or created one.
The reason the FBI is involved heavily is because virtually all identity fraud is related to organized crime and money laundering, the rest are usually linked to insurance frauds. Being the first real case of a major identity fraud online, I wouldn't be surprised if the FBI tries to put their heads on a pike as an example to everyone else.
Immaterial of what they did it for, identity fraud is taken as an exceptionally serious crime and as far as I could tell, they performed a thousand or more 'unlawful identity changes' by operating bots under false names for illicit means. The one exception to this is the use of a pseudonym for anonymity, however it's a colossal stretch to claim your bot army are acting as your pseudonyms for your anonymity reasons.
When I sneak my own soda pop into the movie theater, I have violated their rules. I am running the risk of being kicked out of the theater with no refund and probably be very embarrassed in the process. I am not, however, breaking any laws.
What these people did seems analogous. I don't understand how the FBI is involved.
Due to claiming to be about a thousand people that didn't exist, the FBI is likely investigating them under a major suspicion of being related to organized crime. Incidentally, it's very, very rare that using an unlawfully acquired name isn't related to a serious crime.
If I act like any murderer on the run, the FBI are going to investigate me like any murderer on the run. Similarly if you act like any organized crime money laundering syndicate, you'll be investigated like one!
You seem to be assuming that they fraudulently used the identities of real people. Is there any evidence of that? How do you know they weren't signing up as "John Doe #14812"?
Hardly "hacking," and I have a difficult time understanding how that is at all fraudulent. What am I missing?