The FSFE is using Freenode for our IRC communication and most of the activity takes place in the #fsfe channel. Other channels may be created on the fly and be called things like #fsfe-newcampaign and so on, as it's needed, but in general, there's not enough talk in #fsfe that having any kind of related discussion there would cause a problem in most cases. We have a group registration with Freenode, which means we're responsible for all channels with #fsfe-* names as well as cloaks of the form @fsfe/<name>.
The current administrator for the group registration, and the one who communicates with Freenode staff about changes is jonas (@fsfe.org, of course).
If you want to have an FSFE cloak enabled for your Freenode name, please send a mail to contact (a) fsfe.org. In order to have an FSFE cloak, you must: (a) have your name registered with NickServ (see the Freenode knowledge base for information), and (b) have an account on the FSFE's systems (meaning you're either a volunteer, fellow or staff). Please see this Wiki page about volunteer accounts and how to create one.
All cloaks are generally of the format "fsfe/<username>" where the username is your username in the FSFE's systems. Current staff can be identified by the cloak "fsfe/staff/<username>".