Anyone in control of a UAV,('drone'), requires PPL theory and possibly an ASIC - anyway, enough that CASA knows all the 'legal' operators. So, presumably the Greens/PETA/whoever will be doing this legally which means their operators will be identifiable.
Enter CAR 157........ not below 500ft over anyones' property without written permission. Without this, and a complaint to CASA should see them grounded. I'd say that anyone with any intensive animal production facility should place a public notice in the Australian (?), to the effect that no low flying permissions exist or will be given over the property, and that frequent shooting may take place over said property for the purpose of pest control and that this notice is solely for the protection of the public.
happy days,