No, it's stealing, which is a violation of one's rights. I may sound heartless, but just because somebody is less fortunate than me doesn't mean I need to pay for it, when I've done nothing wrong and earned the money for myself through my own hard work.
Don't get me wrong, if I see a poor bum on the street, I have money that I myself don't need for me and my family, and I can trust that the bum will use it wisely, I will make a donation. But to steal, even for the "right reasons", is still stealing.
I think the big question is "Is it right to steal from honest rich people?", i.e people who earned it fair and square. In that case, no. If they didn't earn it, they are thieves themselves.