Even with the big revenue, Sony still lost a lot of money because their expences are more than their income. The $170 million dollar was not their only expences for that year.
To take a hypothetical example, it doesn't matter much if someone makes 1 billion dollar a year if they had to use 1.5 billion dollars to achieve that income. The final result will be that they lost money overall, and that is the situation Sony is in right now.
Sony spends more money than they make. And when they have to spend $170 million extra that they didn't plan on, this will affect their budget. I'm sure that they will manage even with having to spend $170 million dollar extra, but when their total net income is currently nothing, getting more expences is something that they really want to avoid.
About the creditcard, i agree with that. I guess it depends on what bank you have as well. In my bank, i'm 100% protected against creditcard fraud. It doesn't cost me anything extra. So if someone should steal my card and take all my money, i'm not worried because i'm covered by my bank. VISA also have protection against scams (i've been scammed on Ebay twice (i bought and payed for something that i never recieved) and i got full refund directly from VISA both times
Naturally i don't want to get my creditcard to be abused, but i'm glad that i don't have to worry about losing money at least.