Max Dog Brewing sells canisters of nitrogen for carbonating beer—or killing yourself, depending on who you ask.We asked the man behind the company and euthanasia advocate Dr. Philip Nitschke, who in 1996 became the world's first physician to administer a legal, lethal injection in Northern Australia. The Australian government later quashed the North's euthanasia law, so Philip set up an organization called Exit International to help elderly people end their lives. Since then he's pioneered several suicide devices, written three books, and formed a political party, all in the pursuit of legalized euthanasia.