Hackers broke into Sony Corps computer networks and accessed the information of more than 1 million customers to show the vulnerability of the electronic giants systems,the latest of several security breaches undermining confidence in the company. LulzSec,a group that claims attacks on US PBS television and Fox.com,said it broke into servers that run Sony Pictures Entertainment websites. It published the names,birth dates,addresses,emails,phone numbers and passwords of thousands of people who had entered contests promoted by Sony.