Three Chinese traders earned more than $4 million in illegal profits after they hacked into the computer systems of prominent US law firms and stole nonpublic information on mergers and acquisitions, according to a federal indictment unsealed on Tuesday. According to The Wall Street Journal, the allegations are the latest alarm bell for law firms, which have long been considered vulnerable to cyberattacks. The traders bought shares of at least five publicly traded companies, including drug and chip makers, before the firms announced the deals, according to an indictment from the Manhattan US attorney’s office. The traders learned about the deals by gaining access to email accounts of law-firm partners working on the transactions, the indictment said. Prosecutors said from April 2014 to late 2015, the traders took millions of documents from two law firms’ servers.