[gaius]

I've seen this happen too. But people who wanted to work for company X for whatever reason, not for IBM (or whoever).

Now they work for IBM, and all the things they did above-and-beyond their job description are now billable. Now their incentive isn't to help company X that they wanted to work for, but to screw company X for every nickel-and-dime because that's where their new employer's revenue comes from. And they know all the skeletons in the closet and all the pain points.

Stab good people in the back and you make powerful enemies, the managers of all the company X's out there never learn this lesson.