Vance/Moody/Potter
I don't know if I want to wait for approval before we start tracking them, to be honest. We need to at least have a start on where they seem to be hanging around, so that we can post warnings to not go there until the situation is taken care of.
We're also going to need to set up a schedule for people to be available to cast the Patronus Charm, so that we're not all out at the same time.
Other people who might be helpful in doing this might be Neville, Snape, Remus, Hermione, Ron, Dorcas, and Ginny.