Yahoo users may have benefited most from the “Snowden effect.” The tech company was a laggard when it came to security practices until the NSA leaker’s disclosures made clear the extent to which weak security practices by tech companies are being exploited by talented hackers. It’s since hired a respected security researcher, Alex Stamos, to beef up the company’s practices, and the results have been relatively swift, starting in April with a roll-out of encryption on Yahoo’s services so that it’s not as easy for the NSA and other intel agencies to suck up data — sometimes of the intimate variety – en masse from Yahoo users. At Black Hat in Las Vegas on Thursday, Stamos announced that the encryption train is making another stop. Yahoo plans to add end-to-end encryption to Yahoo mail, following in Google’s footsteps.