Just like in the real world there are also all kind of people in the VR; lawful people and those not following the laws of the companies. The huge mass however does not even know about the cyberwar going on.
The corporations are not that ignorant however. All of them got their hackers and their hunters, and of course they got their security systems.
Hacking is a dangerous activity. Due to the inevitable fact that the human brain has to be linked to the machine the flesh is in danger as well. Headaches that make one crawl up walls are a usual work risk. Especially for the new folks.
There are even rumors that bodies have been found. Still linked to their decks. Their brain burned out. If you want to belong to the elite you know how to make a run. Hit hard and fast. Then know when it is time to retreat.
All decks got more or less efficient security measures in effect. So the risk for your live is merely a result of bad constructed hardware - 3rd grade stuff or homebrewn gear. It is nothing a pro really has to worry about.
Despite the risks, no firm could survive without skilled console cowboys doing the dirty work for them; infiltrating the enemy systems; stealing; sabotaging.
It is a tricky job, but also a very well paid one. If you got what it takes to play the 'game' any you menage to get the attention of a corp you won't have any monetary worries anymore.