Police in Vietnam have arrested four men accused of defrauding more than 5,000 Americans trying to buy coronavirus protective equipment online out of nearly US$1 million, the Ministry of Public Security said on Thursday.The arrests of the four, aged between 22 and 36, were made following a joint investigation by the ministry and US Department of Homeland Security’s Office of Homeland Security Investigations, the ministry said in a statement on its website.In March, the four began operating 110…