Sony’s troubles just keep mounting. Now it’s the target of a class-action lawsuit claiming that the company’s negligence led to the theft of personal data on more than 100 million of its customers.

The lawsuit follows a massive attack on Sony’s online gaming networks, the PlayStation Network (PSN) and Station.com. Hackers broke into the network and stole sensitive information about more than 100 million PSN and Station.com users — including potentially credit card numbers. The lawsuit cites some confidential witnesses that claim Sony’s network security was inadequate and vulnerable to attacks.

Sony finally brought its beleaguered online gaming network back online nearly a month after hackers were able to break in. Sony laid indirect blame for the PSN’s downtime on hacktivist group Anonymous, which typically rallies a group of loosely connected hackers under moral or political banners. Anonymous has denied that it was involved in breaking into and bringing down the PSN.

The network was offline for 24 days. PlayStation 3 and PlayStation Portable owners were unable to download new content for their games and play online with other players. The downtime came at a critical time for two major releases — Portal 2 and Mortal Kombat, both of which prominently featured online play and had received a good deal of critical acclaim.

Sony offered PSN users free games and a whole batch of other welcome-back goodies — like free subscriptions to the company’s premium PlayStation Plus version of the PSN — to entice players to continue using the PSN. The packages will probably appease a large number of console and handheld gaming device owners. But a lot of gamers — myself included — already own those Triple-A titles, and find they aren’t really worth as much as they used to be.

Sony’s online network is a critical service that competes with Microsoft’s Xbox Live online gaming service — as well as other online gaming services. There are also 948 games now available in the PlayStation Network store, as well as 4,000 pieces of add-on content for games. VentureBeat previously published a timeline for the PlayStation Network outage. You can view the full video of Sony Chief Executive Kazuo Hirai (pictured above) detailing the return of the PSN at the PlayStation blog.

We’ll be exploring the most disruptive game technologies and business models at our third annual GamesBeat 2011 conference, on July 12-13 at the Palace Hotel in San Francisco. It will focus on the disruptive trends in the mobile games market. GamesBeat is co-located with our MobileBeat 2011 conference this year. To register, click on this link. Sponsors can message us at sponsors@venturebeat.com.