Sony has hired a team of private cyber crime investigators to work with the FBI in catching the hackers behind its recent security breaches.

The Japanese electronics giant has appointed three security companies to help with the investigation this week, and to make sure its network infrastructure is secure in future. These are internal audit firm Protiviti, Cyber security supplier Guidance Software and Data Forte, a computer forensics firm led by a former agent at the Naval Criminal Investigative Service,

The appointments come as Sony customers are preparing a class action lawsuit against the company. Proposed by Canadian law firm McPhadden Samac Tuov on Monday, the suit seeks over $1 billion in damages. This will help cover the costs of credit monitoring and fraud protection services for customers whose data has been stolen, the suit says.

The lead plaintiff is Natasha Maksimovic, 21, from Mississauga, Canada. “If you can’t trust a huge multi-national corporation like Sony to protect your private information, who can you trust? It appears to me that Sony focuses more on protecting its games than its PlayStation users,” she said.

Sony has offered affected customers up to 60 days of free membership to its gaming networks as compensation.