They are known as travellers or pikeys. They usually have Irish accents but are despised in Ireland also by most Irish people. They think of themselves as a separate race from settled people and are treated with such disrepsect, so you can't blame them for being hostile outsiders. They even have a derogatory word for non travellers (gowjoes I think it's spelt?), they aren't protected enough and this needs to change.
Label: no hate