I think that it can be really silly idea to pay taxes on gambling if it is prohibited

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If gambling is prohibited in the country, then even if you really want to, you will not be able to pay the tax in this case. Anyway, voluntary payment of a tax cannot ensure its guaranteed fulfillment, unless it is withdrawn when the winnings are issued/withdrawn.
It is a very curious case, because if one really wanted, one could actually pay taxes for gambling winnings in a country where gambling is illegal, though it would require to lie to the government about the source of those earnings (which is illegal itself) but I think someone could get away with it if there is not much scrutiny, still it would be indeed silly for someone to pay them in that way.
I have encountered so many people gambling online who are from countries where gambling is alledgedly outlawed, so much so it gives me the impression the ban on gambling is not even being enforced in those nations.
As for myself, I don't have to pay taxes on my gambling earnings as I am at a net loss this past year.