Greenpeace is leveraging social media in its push for a zero deforestation target in Brazil. The environmental activist group has launched a \"Brazilian Friend Finder\" to support its petition drive to counter a proposal to weaken Brazil\'s Forest Code, which mandates how much forest farmers and ranchers are required to maintain on their land. If the petition gets 1.4 million signatures – one percent of Brazilian voters - then Congress must formally consider and vote on the proposal. Greenpeace\'s proposal calls for zero deforestation, with exceptions for small farmers, indigenous communities, and \"responsible logging\". Greenpeace\'s campaign comes ahead of the Rio+20 conference on sustainable development, which will be held in mid-June. The group says that passage of the Forest Code revision could send the wrong signal ahead of the conference, which will attract political and business leaders from around the world. Brazilian President Dilma Roussef is expected to vote on the new Forest Code in coming days. Environmentalists are calling for her to veto the legislation, which has been pushed by the agribusiness lobby.