Update from Ruairi Donnelly, the Executive Director at Raising for Effective Giving: "Ferruell's matching drive has been going on for a while behind the scenes, as he had a preference for doing it in the Russian poker community first. No limit was declared (but the implicit understanding was 'in the tens of thousands'). As donations were slowing down, our ambassador Liv Boeree shared it on Twitter. Ferruell has now confirmed that he'll match donations up to $50,000. [Roughly] $30,000 have already come in."