I had been an employee, and later a contractor, for a system vendor in the transportation industry. I got a call from a guy who I used to work with, who now worked for the company to which my ex-employer had sold their transportation business. They needed to duplicate a product made about 8 years before, and had found the manufacturing drawings (case, PC board schematics and layout, wiring, etc.) but couldn't find any source code for the firmware. I had to tell the guy that I had source code backups of the items that I had worked on as a contractor (as agreed), but nothing for the device he had in mind. He told me they would be happy just to recover the firmware image from the programmed processor (I think a Dallas DS5000) in one of the field units, but that the specification had called for the microcontroller firmware to be read protected, so they didn't expect to be able to recover it that way... I wished him good luck, but told him I couldn't help.