One of the companies here in my little town of Billings (an engineering firm) was using all unlicensed copies of AutoCAD. One disgruntled employee ratted them out and they ended up with $500,000 in fines, plus they had to buy some 50 licenses of AutoCAD. This was 17 years ago now. You can believe what you want to believe, but I have seen companies get hit hard with fines for unlicensed software first hand, and fighting it is a lose/lose situation.
I dug pretty deep into the legitimacy of the last letter I got, as well as consulted with our lawyer because I have had fishing letters before that try to scare you into buying licenses and whatnot, but this one was indeed legitimate. You can tell the fishermen to pound sand, but there are some firms you tread a little more lightly around. My company has spent well over a half million in defending against frivolous lawsuits in the past, and when we win, we still lose. I didn't pay these guys a penny, but I sure as hell made sure nobody in the company had any unlicensed software. CYA...
I completely hate the idea of paying Adobe nearly $1000 per year to use their software, particularly since I often go a month or more without using photoshop or illustrator. I got by for 7 years on photoshop 5.0, and then for many more on cs3. It sucks I can no longer buy a current version and just own it, and I have a hard time spending $2500 for a 2 year old version that will never get updated again.