16yo brother came out having +4BTC he made in a shady way

I'm a little bit confused on where to ask this, thought about law subbredits but this case is uncommon and heavily related to bitcoin

so my 16 yo brother is a pure geek, he spend all of his time on PC, today he came out saying he made 4 BTC which is around $150k

I first thought it was a joke, but nedless to say i went to check and found around 4 BTC on his electrum wallet, i also asked him about every detail of the story and to make it short, he milked all those funds from a crypto gambling, he also thaught me the process and did it on last time in front of me. he did not just gamble his way up here, rather used a vulnerability.

Some details needed to answer my questions :

-The gambling website is not some big corporate website, it's a small yet reputable website that has been around for 8 or 9 years, I got all this infos from bitcointalk and they seem to have huge player base but nothing near stake or similar ones

-They don't deal with FIAT currency which made me think they're not a regulated gambling company

-There is no 'About us' or any information that makes it believe there is a legal entity behind the website, they purely relay on their acquired reputation through out the years

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Now the questions :

What will happen if we decide to keep the funds?

I highly doubt they ever have the ability to sue him, i doubt the guys behind it pay any tax or whatesover from it to even consider mentioning their little buisness in court

Would it make it worse if my brother decide to continue doing his little tricks until they notice?

I wanna hear your opiniong guys, i'm clearly lost and this is the craziest thing i've ever experienced in my life

My DMs are open for unconventional opinions or tips you may not want to post here aswell, as long as you know what you're talking about

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