The Tailies
The people who roughed up Jin are also survivors of Oceanic 815. They were in the tail section of the plane. They include Ana Lucia, Mr. Eko Libby and Bernard, who is the husband of Rose, a survivor who has been hanging with Jack and company. Rose, by the way, has been helping Hurley figure out a way to distribute the food they found in Desmond's hatch. They end up having a big old well-deserved beach party.