About 7 years ago I worked at a bespoke software shop that decided to sell one of its products. It was an end-to-end operations suite for some industry. Well, this industry wasn't known for being super technological, so somehow we ended up providing third-party technical support for their servers and IT infrastructure instead of farming it out to independent small business IT consultants.
One day, a customer's server encountered disk corruption. The server we had sold them was configured with an Adaptec RAID controller, set up for a RAID 1 mirror. Their application database was toast. They hadn't performed backups in months. The backups they had performed were unusable. They ended up losing 8 months of data. They hired an IT consultant to handle this investigative work.
Phone calls ensued, and the sales manager (known for promising impossible features) apparently told them it would be taken care of, and wrote it up in a contract.
The sales manager promised the customer that we would ensure that the application database and any other application-related files would never be replicated by RAID controllers if the files were considered to be corrupt. No configuration should be necessary either. Yep. We were told to deliver this functionality in 2 weeks, or the customer would fire us.
So the program manager -- who had some large enterprise CRM products, and other serious development successes, under his belt -- and I had a meeting with the COO, and the sales manager. The program manager was detailing how insane, impossible, and insanely impossible this was. The sales manager (military background) would simply scream in his face (literally!), "I don't care! How hard can it be to make the RAID thing not RAID?! Their data would be fine on the other drive if the RAID thing hadn't screwed it up!"
At the end of that meeting, the program manager quit with a zero-day notice. So I was now tasked with this. Over the next week, I petitioned both Adaptec and LSI Logic to provide an engineer for a conference call, simply to laugh in the face of the sales manager.
Ultimately, they obliged, and held up their end of the bargain. And they went into detail how ridiculously unfeasible it was. The guy from LSI was particularly harsh - he didn't sugar coat anything.
I didn't have to implement the feature. One I did have to implement was a custom security scheme requested by a customer, that would allow them to toggle any of the application's controls - on a control by control basis - as visible, disabled, enabled, read-only, or read-write. In theory, there were 146,000 combinations. And if you accidentally screwed up by say... disabling a control group, you'd have inadvertent side effects. Needless to say, when I was given the ultimatum that it had to be implemented, I also quit with a zero-day notice.