I just read a great article by Ishita Palli on detailing major potential ramifications of a cyberattack on one or more of the world's largest banks. 

It's one of those things that you don't really think about, but when someone says it you smack your forehead and ask why you hadn't thought of it yourself: today's banking system relies upon the fluid, fast, and reliable movement of capital transactions between not just the largest banks in the world but down to the smallest local banks. 

Think on this: the five largest banks in the US move 50% of daily transactions. At the end of day one, it's estimated that 6% of institutions will run out of end-of-day reserves. Extrapolate that out an extra day, or a week, or a month...

Anyway, read this article and think upon it, and have a great weekend!