Brazil holds a national referendum on Oct. 23 on a government-proposed ban on the sale of firearms and ammunition to civilians. Below are some key facts about the ballot: - It is the first time a nation uses a referendum to decide whether to ban gun sales, according to Brazil's government. - Voting is compulsory in Brazil, where about 121 million people between the ages of 18 and 70 are expected to participate. Some 407,000 electronic voting machines will be used... (GunPolicy.org)