Is that actually true? I've never heard of a IBM union for tech employees. Is Alliance for programmers? Are they officially unionized? It seems ambiguous from their about statement [1]:
> Alliance@IBM/CWA Local 1701 is an IBM employee organization that is dedicated to preserving and improving our rights and benefits at IBM. We also strive towards restoring management's respect for the individual and the value we bring to the company as employees. Our mission is to make our voice heard with IBM management, shareholders, government and the media. While our ultimate goal is collective bargaining rights with IBM, we will build our union now and challenge IBM on the many issues facing employees from off-shoring and job security to working conditions and company policy.
There is WARN to consider, which is why they can't just do mass layoffs without lots of notice.