I understand that breaking into a computer alone wouldn't cause anyone any harm (other than economic burdens needed to clean up your mess), but the bill specifies actions that would cause physical or economic harm. There are lots of people that would like to break into a computer with the desire to directly or indirectly endanger people's lives or the economy. Here are some dangerous scenarios that would satisfy that very prospect:

1) Air traffic control systems. Flights that were once in the air are now mysteriously on the ground...in several pieces. Result: lots of innocent civilians killed.

2) NYSE stock systems. "Holy sh1t! AT&T, Qwest, and MCI stocks are all down 3000 points! SELL! SELL!" Result: economic recession/depression.

3) Law Enforcement systems. "I'd like to sell you a list of every American undercover FBI/CIA/DEA/NSA/OCB/NRO/ATF/Secret Service agent in the world and their locations. Result: lots of dead law enforcement agents.

4) Power Plant systems. All the power goes off in Las Vegas because Hoover Dam has gone offline. The Strip is littered with automobile accidents.

I think the bill was written for the people who would consider this sort of thing.