The US Justice Department opened an antitrust investigation into the hiring practices of major tech companies in Silicon Valley like Google, Apple, Yahoo, and Genentech. While these companies aggressively compete for top talent, lawyers and recruiters said there is an unwritten "gentlemen's agreement" that companies do not poach employees from each other, but rather compete through legitimate hiring processes. The key question is whether this agreement constitutes anticompetitive behavior under antitrust law.