Here are the updated instructions for joining the PwC Alumni group on LinkedIn as of late 2008.
1. *** IMPORTANT *** If you did not previously work for PwC, PW, or C&L, you are not eligible for the group. This includes all of the recruiters who regularly request group access and are denied. Please don't click the link if you didn't work for the firm.
Let me state that again because it is regularly ignored.