Two Brazilian activists, Almir Nogueira de Amorim and João Luiz Telles Penetra, have been brutally murdered in the Guanabara Bay. They were fishermen fighting against the construction of gas and oil pipelines by a Brazilian multinational, Petrobras, which disrupted their fishing and livelihood. They spoke at the recent Rio + 20 conference. 
http://climate-connections.org/2012/06/29/action-alert-denounce-the-murder-of-fishermenactivists-in-rio/