It's very important to:

• Use a different username and password for different Social Media services. Don't forget the LinkedIn incident.
• Have a plan for the case of account hijack. What are you going to do.

Facebook

Site administrators will have to use their personal accounts to be productive. Period.

• Be aware who in the company has the privileges to publish on FB as your NREN.
• Asign your staff different administrative roles like "Content creators" or "Moderators" instead of "Managers".

- "External helpers" on FB - people that publish photos or update the posts for you. Periodically we should check all the administrators and decide whether they still need administrative privileges;
- same username and password for multiple social media accounts. Remember hijack of at least 1 Million LinkedIn passwords. Good u&p management and different passwords for every social media app should do the trick - sounds obvious, and we all already have this one covered, right  
- do you plan in advance in the case of hijack. Do you have your account connected to the mobile phone for password retrieval? Have you provided phone numbers for the check?
- do you use double security check (password+confirmed desktops) on Google+ and other google connected accounts.