jason glassberg joins us via skype from seattle. it is unusual the way this happened. it happened at the pos terminals. explain how you think this happened. >> that is what makes this attack unique. we expect these kinds of things to happen through web vulnerability, and it appears that the point-of-sale terminals, the machines we swipe the cards, were the ones that suffered the vulnerability. >> how can a company protect against something like that? how is it different from protecting against online breaches, for example? >> you would think the company would have more control over the access to these point-of-sale devices. they should not be available on the web, they should not be accessible from the web. it points to some inside phone or ability or exploitation, whether it was an inside job or someone had inadvertently allowed some religious software to run and gain access into the company. >> why would the secret service be investigating this? >> it certainly is alarming. this is not the kind of attack one normally expects, especially of this scale. what makes it s

. >> jason glassberg, thanks so much for weighing in. we will continue to follow this story as it progresses. 18 months after he went public, facebook is planning its secondary offering. mark zuckerberg and mark andreessen are taking part. ♪ >> this is "bloomberg west." i'm emily chang. 18 months ago. joins the s&p 500. cory johnson is back with more. how big a deal is this? >> it's a great question. i don't have a great answer for you. you have got andreessen horowitz really taking a lot of the table here, taking some profits with the share prices. it's a very expensive stock. what mark zuckerberg is doing in his sale is giving exact opposite message, where you see him selling so much and you think, what is this guy doing, he says he's selling it for a tax bill. he's really doing is exercising a number of stock options. it's only bullish. it's only a bet on the company that it will be worth a lot more later, so he wants to take the tax hit now to avoid the tax hit later. would you look at what mark is doing as part of this, it is someth