Anti-1080 campaigners say more protests are likely.
1080 is used throughout New Zealand to control animal pests, including possums, which spread the livestock disease, bovine tuberculosis.
In its fourth annual report on the aerial use of the poison, the Environmental Protection Agency says there were 34 incidents and complaints about 1080 reported to it in the past year, double the amount received the previous year.
People who removed bait and 1080 warning signs accounted for about half of the complaints to the EPA.
However, the group Farmers Against 1080 says a great deal of work is done to discredit anti-1080 groups, and another organisation could be removing the warning signs to make them look unreasonable.
Spokesperson Mary Molloy says the group stays within the law and anti-1080 campaigns are likely to increase.