ABC (Australia) employee caught mining for Bitcoins on company servers
thenextweb.com
thenextweb.com
Your underlying question seems to be "is it best to use ATI or NVidia cards for a render farm", I don't know the answer to that. Probably depends on the specific rendering software used.
C'est la vie.
The main danger is that the target notices that their machine is using 100% CPU and removes the bot. It is easier to notice CPU load (heat, fan noise, prominent position in Task Manager) than network load.
Everybody uses company resources for the company gains. Only. In the end of the month, the company pays you something called 'salary'. You use the salary as you want. That's your gain. And your only gain. (Okay, may be bonuses, equity...)
That's what I know (and learned) so far.
I don't think that's our only gain from working at a company. Working at a company (1) gives you experience working on projects that you might not be able to get without the required trust in your personal brand, (2) socialises you with technical people from your discipline, and (3) increases your job security.
I particularly consider (2) very important. Of course, you can quit your job and create as startup, but: you're creating risk for yourself and there are things which companies provide employees which have to be built over time.