James Browne (Wexford, Fianna Fail) | Oireachtas source

To be clear, it is not the behaviour of the perpetrator that is considered serious; it is the effect on the victim. It is if it seriously interferes with the victim's peace or privacy. It is from the perspective of the victim as to whether or not it could be considered "seriously". As I read it, the victim's voice is what is relevant in determining whether something has been serious or not.