As a born and bread corporate (mostly banks) corporate IT guy, I used to frown upon this behavior. Then I got one of my bigger career breaks because the finance team went behind IT, bought a software and installed it in a machine which kept under their desk. They further hired people from an IT service company to configure the machine.
The configuration was so bad that it exposed the company's network to whole wide world. Google contacted the company and after searching high and low IT security managed to track the pc down and take it away. Finance team promised to hire someone with skillset required to run the software in a closed environment. And that's how I ended up getting my job.