Lula arrest in Brazil graft probe raises risk of Rousseff's fall

By Anthony Boadle and Alonso Soto BRASILIA (Reuters) - The implication of Brazil's ex-president Luiz Inacio Lula da Silva in a graft scandal at state oil firm Petrobras has reignited opposition hopes of unseating his successor Dilma Rousseff and increased the risk she may not finish her term. The federal police's decision to take Lula in for questioning on Friday raised the temperature of Brazil's political crisis on the streets, with demonstrators for and against the ruling Workers' Party clash