In several ways Trustroots relates to Facebook.
It's possible to log in with Facebook. It's done in a privacy friendly way that reduces exposure to the Facebook API for those who don't want to ever use Facebook to log in.
Users who log in with Facebook can choose to use their Facebook profile image as their Trustroots profile image. This is not ideal for those who block all Facebook domains or who simply have their browser set up to not allow cross domain images.
The Facebook group is a place to discuss TR for people using the platform but should also serve the purpose of allowing other people who have no account to just join and get a feeling of trustroots, as well as just to expose ourselves, so that folks can see how many we are (a lot :wink:) and feel like this is something they want to be part of and not a dying platform with no users.