Hey Karl,
Campaigns like the day we fight back aim for maximum impact and try to reach as many people as possible, that includes those on corporate networks.
I agree the solution is just don't use facebook but that's often easier said then done.
I managed to kick the Facebook habit. Though Google will be a bit harder.
While the P2PF encourage people to use free and open alternatives we don't have any kind of special policy on social media. Our presence on corporate networks is maintained by volunteers, members of our community who are also active users of those platforms. I think it's useful for orgs like the P2PF to have a presence on those networks but to a degree. Personally I prefer forums such as this mailing list which are independent and open to all.