I'd suggest no one should investigate. So you lost your Bitcoin from some massive fraud? Too bad. That's the cost of playing that game. You should not get a free pass when you ask your government for assistance, and you should not have your government investing time and money looking into massive fraud concerning Internet Fun Bucks. You assume all risk when using this kind of money.
But you could tax someone for getting free gifts "in kind", so if you donated GPU time to do protein folding for GlaxoSmithKlein and they rewarded you with some internet points, they might be taxable on the difference.
Video games have all kinds of gold etc. that you can use to buy items. People will pay you real money to get your video game points if the video game is popular. So now is everybody who plays a popular video game committing tax fraud unless they report their gameplay to the IRS, because they earn points which have monetary value? That's not going to go over well.
They seem to want to go with something like it's not taxable unless you cash out. But that's a whole different kind of mess. If you trade somebody your Roblox points for their Fortnite points, is that cashing out, or are you both just trading your non-taxable thing for a different non-taxable thing? Is there any reason for this to be different than trading your sword for a crossbow within a single game? What about games that share worlds? What about games that have cryptocurrency in them?
The whole thing is a mess because "anything of value" is too broad to be practical, but narrow it an inch and you have a loophole.
I believe that the government should tax transactions involving money. If you cash out your bitcoin, then that's income, and should be taxed. I don't think unrealized gains of bitcoin should be taxed because bitcoin isn't money
