Summary Offences Act 1981, s 4
Offensive language in a public place is a minor criminal offence in New Zealand. In some cases, repeatedly swearing on a protest could result in a conviction for this offence.
However, this will depend a lot on the particular circumstances, including exactly what you said, how often, and so on. The judge will take into account your right to freedom of expression under the Bill of Rights in deciding whether on balance how you behaved was serious enough to breach the criminal law.
Case: Stemson v Police [2002] NZAR 278 (HC)
In some cases swearing at the police on a protest could also amount to offensive language. However, the courts have said that police officers (along with other professionals who deal with vulnerable people like WINZ staff, teachers, nurses and doctors), should be expected to put up with a greater amount of abuse than ordinary members of the public. The judge will take this into account in deciding whether on balance your behaviour amounted to “offensive behvaiour”
Summary Offences Act 1981, s 10
Threatening a police officer could amount to the offence of assaulting a police officer, which is punishable by up to six months’ jail or a fine of up to $4,000. This is because an “assault” includes the threat of an assault.