Screwed by MS over select
We ran Select with squeaky clean control. There was no usage beyond the contract terms. Maybe 7 or 8 years ago MS wanted us to move to SA (at an additional cost of 7 figures). When it became clear that we weren't going to, MS sent in "independent" third party auditors - as was their right under the Select license. We were told that no such audit had ever failed to find some violations and our best option was to roll over and pay up for SA.
After a few days looking at our license control system the auditors seemed happy and told us they had never seen such scrupulous control of licensing as ours.
Having fed that back to MS the auditors came back looking unhappy and got busy again. I suspected they'd been given a strong imperative from MS to deliver some evidence of violation - like "if you don't find a problem we'll be using different auditors in future".
They found an issue. We had a stack of downgrade licenses. There was a point in history when we could only buy PCs preinstalled with Win95, we wanted to stay on Win3.x and update the entire PC estate later in a controlled and properly managed manner. MS required that we pay for a "downgrade" licence for each of those PCs to use them with Win3 instead of the shipped Win95. In itself that tells you something about MS, so little confidence in their own new product that they have to charge extra if you choose to stick with the older version - so each PC effectively had to have 2 windows licenses. And of course they could announce artificially inflated figures for the adoption of the new product.
Moving forward in time to the audit 5 or 6 years later, all our estate had indeed been upgraded but we had no evidence of the originally shipped licenses for those PCs - notwithstanding that those PCs were obsolete, few if any still extant (and the manufacturer had stopped making PCs in the intervening years and unable to assist). So all they had was a pile of downgrade licenses and an estate of upgraded PCs. From my perspective a downgrade license implies that there was a license to downgrade from, especially as it probably dated back to the time when MS were requiring that manufacturers buy a Win license for every PC shipped regardless of whether the user wanted/needed windows. But the auditors disagreed with that logic.
My employers struck a deal to close off the issue - they agreed a payment for the alleged violation but were not forced into buying SA and payment was a few percent of what SA would have cost. That prevented any risk of allegations going public, however ill-founded, that a major corporate was guilty of software piracy. There may have been other considerations - we very probably had other completely unrelated commercial involvement with the auditors, they may have been customers of ours and looking at the bigger picture it may not have been in our best interest to upset their lucrative work for MS.