Yahoo apparently took two years to investigate and tell people that its service had been breached, and that over 500 million users were affected. Amid the announcement, a user is suing Yahoo, accusing the company of gross negligence. From a Reuters report: The lawsuit was filed in the federal court in San Jose, California, one day after Yahoo disclosed the hacking, unprecedented in size, by what it believed was a "state-sponsored actor." Ronald Schwartz, a New York resident, sued on behalf of all Yahoo users in the United States whose personal information was compromised. The lawsuit seeks class-action status and unspecified damages. A Yahoo spokeswoman said the Sunnyvale, California-based company does not discuss pending litigation. The attack could complicate Chief Executive Marissa Mayer's effort to shore up the website's flagging fortunes, two months after she agreed to a $4.8 billion sale of Yahoo's Internet business to Verizon Communications. Yahoo on Thursday said user information including names, email addresses, phone numbers, birth dates and encrypted passwords had been compromised in late 2014.