Reueters

(Reuters) - Shares of Sony Corp (6758.T) extended losses to trade down as much as 5.2 percent, hitting a one-month low on Thursday as investors worried over the widening impact of a massive leak of personal information of users of its PlayStation network.

Sony said on Tuesday that hackers had breached the network a week earlier, compromising confidential information including the names, addresses and possibly credit card data of 77 million users.

Experts say Sony could face legal action across the globe due to the incident.

The stock is now down more than 8 percent this week with investors nervous about the fall out of the data leak episode that plagued the company.

There is concern that loyal PlayStation gamers could ditch Sony in the wake of the data theft. The theft could cost the company more than $1.5 billion, or an average of $20 for each of the 77 million customers whose data was compromised, according to Ponemon, whose firm specializes in securing information on computer networks.

Security experts say that Sony needs to account for the loss of that business -- as well as damage to its brand -- when it tallies up the cost of dealing with the breach. Other costs include notifying customers of the attack and bringing in experts to cleanse its network.

http://www.reuters.com/article/2011/04/28/us-sony-stock-idUSTRE73R0A420110428

One disaster after another for Sony.

See this was a more reasonable number in terms of cost. However how much the shareholders lost might even be greater in the end, well investors typically have to accept risk, but still sucks for them. 

$1.5 billion would be pretty nasty for the games division (even if to Sony as a whole that's relatively miniscule). At the very least this is a pretty big blow to their image

By the way, if I am reading the chart correctly, if tomorrow it dips further it will be really bad news, as it will be the lowest in two years. 

Honestly I think some investors might be jumping the gun, but you can never tell what the effects of something like this truly is. 

As a reference the RROD problem cost MS 1 billion, so losing 1.5 billion in a couple of weeks is going to hit hard.

ouch. That's double of what Activision-Blizzard net income was for last year

$1.5 billion is the difference between Sony making a profit and them losing money for the fiscal year. They don't make Apple or Microsoft kind of profit.

When Microsoft can pull in $10-15 in profit each year, it's big, but not critical.

Sony however is lucky to make $1.5 billion profit total. So that amount could put them into loss.

It will not cost SONY $1.5 billion....

 Also the firm reporting this originally said $318 per account. Now its $20 per account. The figures are $x for security updates, $x for employee overtime (two weeks worth akin to the lead up to a console launch), $x opportunity cost for lost revenue while PSN is down, $x opportunity cost for PSN over ~2 years (PSN revenue will be down over what it would of been without the breach).  

 All in all i would estimate SONY will spend about ~$50 million on this, maybe another ~$5 million on the lawsuits they will win (your phone number, address, name, PSN username, PSN password don't need to be encrypted. PSN details are SONY's businsses and ph numbers, names and addresses are public information freely avalible little things called phone books). In addition to this they will have about $500 million revenue in opportunity cost, maybe $1 billion if news outlets keep reporting the worst case senario. This means that SONY will have up to $1 billion revenue less then what they would of had. This is likely to occur over about two years imo - after which time most of the general public will have forgotten about this.

MS lost way over $1b

their reserve for RROD problem was itself $1.5b and even then they allocated some more to it after the rrod problem continued