The IRS will concern itself with anything connected to a finacial gain, not just "money" per se.
If one is enriched in any form to which a monetary value can be assigned then he/she may be liable for tax.
If you "win" a prize/car, for example, you do not owe taxes on the prize/car itself, rather on its dollar value on the market, same as any/all personal gain, bit coins included.
The IRS will concern itself with anything connected to a finacial gain, not just "money" per se.
If one is enriched in any form to which a monetary value can be assigned then he/she may be liable for tax.
If you "win" a prize/car, for example, you do not owe taxes on the prize/car itself, rather on its dollar value on the market, same as any/all personal gain, bit coins included.