Privateering computer systems
In the late 16th century, a small group of sea-going warriors known as the Sea Dogs ravaged the Spanish empire, raiding shipping up and down the Atlantic and as far away as the North American west coast. Though they were not officially part of the British navy, in many ways they did far more to damage Britain's enemies. The Sea Dogs were privateers, attacking vulnerable merchant vessels, killing crew and taking booty. Their most famous member was Francis Drake - or I should say Sir Francis Drake, who knighted for exploits that included his stint with the Sea Dogs.
Privateers were pirates in every sense except one - they were granted immunity by their own government. At different times and places - they operated for more than two centuries - they had direct relationships with the government that sponsored them. Drake "graduated" from privateer and became second in command of the fleet that defeated the Spanish Armada.
Hackers are today's privateers. Not all of them - the majority have no government relationship (and would abhor it) and do their thing for personal reasons, be they kicks or money or both. But the group that hit JP Morgan and several other financial situations over the summer are far more organized than most, and would appear to either have connections with a government - Russia, specifically - or at least be protected by them.
The U.S. has its our own state-sponsored; those working for the NSA are only the best known. (An irony for many reasons.) It's unclear whether the government sponsors privateers as well, but failing to prosecute hackers who attack computers overseas is, in effect, the same thing.
It's warfare by a different name, just as it was in the 16th, 17th, and 18th century. It may be low intensity, but it clearly can do as much damage if not more than an attack by bombs.
As governments countered the privateer threat - and launched their own - the strategy eventually became less effective and died out - after two hundred years. Time is compressed these days, but it's likely going to take something on the order of the destruction of the Spanish Armada to make stopping the widespread attacks more of a priority.