If the incomes were high enough for a living during 20 years, how did he launder all that money for so long?

Just curious, any idea?

There is no reason he would have to launder it at all, it's not dirty money (it's not illegal to sell items in video games, but often against the ToS). He could easily pay taxes on it as business income. Nobody knew he got it illegitimately.

Yes, but business for doing what?

Fabricating and selling digital goods online. Could legitimately expense his computers too (if there was enough to itemize or he formed a corp)

If "fabricating" means violating ToS and probably damaging (or at least impacting) the legal revenue of the companies that owns the games, I can't see how to run a company without hiding the real origin of the digital assets.

AFAIK to sell a digital asset under the umbrella of a legal entity like a company, its origin must be legal too.

If the income is big enough (and it seems so), there must be some kind of legal structure to sustain it for such a long time.

Sounds like he may not have laundered it, just took the risk. As far as I know, there's not much proactive work in the US to ferret out illicit income on its own. It's typically some other activity that manually prompts a look into your finances.

At least now you know who stole your house in UO.