I think you all are picturing something different than what I volunteered for, this is not a committee type thing. This is a staffed (staff is paid; volunteers not) conference where the volunteers are there to do things like ushering, traffic control ( man parking lots and direct traffic), show people how to get from one workshop to another, and set up chairs, stage props, help with arts and crafts and such. There is no need for any volunteer to get a hold of another during off hours. And the only folks we'll need to talk to while "working" will be in the same location as us. This is more akin to volunteering at a music fest as extra hands, than anything else. With 50 workshops and people coming from local schools, as well as from the college itself, there is a need for people to come in for a few hours, do what they are assigned to do and leave - but that's the extent of it.
Since the staff are all paid employees, who work on this year around, they may need to get a hold of each other, but other than the volunteer coordinator none of them need to get a hold of us - and all of that so far has been emails.
As far of as what FERPA covers, I spoke to two separate offices at school, both told me that once those forms are filled out they, give out nothing, at all. It may be different than your experiences, but I have to believe what the school offices ( Student Affairs and Registrar) tell me.
PS: this is a Landline we are talking about - that is unlisted.