FORTUNE — When greenie blogs posted leaked internal documents saying that the nonprofit Heartland Institute, funded by the conservative Koch brothers, had a program to teach global-warming skepticism in the classroom, few were more surprised than Microsoft (MSFT). That’s because the leaks also revealed that the software giant, which has strong corporate policies to combat climate change, was a donor too, giving Heartland $60,000 in software. It turns out Microsoft doesn’t vet its donees’ causes. Any group recognized as a nonprofit can apply for free software. Last year Microsoft gave away $844 million in licenses to 44,000 nonprofits. It does indeed seem that no good deed goes unpunished. —Alex Konrad