I comment on HN because I enjoy it. But I suspect that some people add money to Jonathan's Card because it gives them a feeling of virtue. I'd like to interfere with that feeling.
Honestly, why? You can't scold everyone into "real" virtuous behavior, so why not give them a taste of what it feels like and see if they can get hooked?
Do you believe that people putting money on this card would actually donate it towards a more deserving end?
I (think I) understand your goal here, but ultimately I think what you're doing is either ineffective in or outright harmful towards achieving it.