Reddit's “detectives” figured out that they were dealing with a scam once a user pointed out that the thread author, ZeConfusedOneAgain, posted a fake photo of the children. The photo was identified as fake due to its awful quality and later identified as a flipped version of the original from the website of a real non-profit organization actually providing the children with food and medicine.
Apart from the suspicious image, the Bitcoin address posted alongside it was leading to an online casino. The author of the thread defended this claiming it was for the purpose of avoiding regulation and taxes in Venezuela.
Sadly, it seems the BTC donated so far (around 0.064 or $600 at current prices) were used to pay off ZeConfusedOneAgain's gambling debts, rather than food supplies.