It looks like things just got interesting for people that over power..

http://news.business.govt.nz/news/info/rsm/article/9430

Monitoring improvements for Low Power FM and FM broadcasting
Published: 14.04.2009

MED has recently taken delivery of an Audemat-Aztec FM-MC4 which allows for
more accurate and more comprehensive monitoring of Low Power FM (LPFM) and
FM broadcasting (FMBC services) than current equipment.

This measuring instrument is commonly used overseas, particularly Europe
where it was introduced to help resolve cross-border FMBC interference
issues.
In New Zealand it is planned to use the monitor to more accurately measure
LPFM and FMBC transmission bandwidths and power levels. This is to ensure
our FMBC planning standards are being met, and more importantly, to enable
better monitoring of services likely to cause interference issues for
aeronautical navigational services adjacent to major city and regional
aerodromes.