A USA TODAY motion graphic explaining the steps hackers use to take down servers. A graphic representation of the dangers posed by botnets, stealth robotic computer networks that place malicious hardware on the computers of unsuspecting users. SAN FRANCISCO -- A New Jersey man has pleaded guilty to computer crimes charges for an online attack that caused a massive Internet outage last year, according to federal court documents unsealed Tuesday. The Justice Department says Paras Jha built the Mirai botnet, which operated hundreds of thousands of infected household devices to flood websites with traffic, knocking out services such as Netflix and PayPal. The plea agreement was filed Dec. 5 in federal court in Alaska.