This jackassery is like if DEC had gone after Microsoft for hiring Dave Cutler et al.

If every company always pursued every technicality allowed by our stupid laws, none of us would be free to change jobs.

edit: Apparently I couldn't have picked a worse example :| However, thinking about the similarities, I'm struck by the sense that these companies are basically seizing on a plausible excuse to extract millions from each other. But these actions diminish the autonomy of these programmers, reducing them to property.