Except in many cases, that isn't at all how it works.
Someone will send an anonymous "tip" that a company is using unlicensed software. Often this is a disgruntled employee or ex-employee. Hell, BSA has been running ad campaigns on Facebook for a while now encouraging people to report companies in exchange for the possibility of a small reward.
The software companies (Or BSA on their behalf) will start hassling the reported companies, whether or not it is true. This leads to either a voluntary audit of their licenses (Which still costs quite a bit in time and effort) or legal action. Every instance I've heard of companies going through with the voluntary audit has had the companies threatened with having trivial, honest mistakes punished with large fines and legal action. It's a losing proposition for them, even if they've done nothing wrong, or have small technical issues with their licensing that they've made a good faith effort to have in compliance.
It is a complete shakedown.
It wasn't like that in my experience 15 years ago. I was a disgruntled employee, I sent an anonymous tip to BSA.org, but nobody showed up at my company.
Microsoft is going in the WRONG direction. Their insistence on alerting the mothership every time you compile, open notepad, open your media player, view photos... it isn't good. At all.
As well as the forced updates, some of which render your computer unbootable.
Computers are unreliable, but humans are even more unreliable. Any system which depends on human reliability is unreliable. -- Gilb