Hacker 
You know what being a hacker is about? The Matrix, hardware, software, commlinks and agents? Wrong. It's all about the data. You've got to understand something: everything is data. You are just a product of some data encoded in your DNA with some additional data stored in your brain. When you act, you're just reacting to whatever data you're getting. Data is the most valuable of things. You might have tons of gold, but it just takes one piece of data to get the gold price down.
He who controls the data controls everything. Now think about it: who does? Corps. Where do they store it? The Matrix. Starting to get something, chummer?
The data should be free, nobody should get control of everything. That's why I do what I do. That's why I liberate proprietary data on shadow nodes. That's why I'm a hacker
-------

That's one kind of hacker. Some hackers are just people who take things apart to see how they work, out of curiosity. Some just see hacking as a profitable business with low risks compared to other illegal actions... There are a lot of different ways to consider hacking.