I want to share my worst experience I ever had during my 40 years of ham radio operation.
This morning, between 20-21 UTC we were working with State side on 12 meters band. 1 kHz below of our QRG someone was also making QSOs in our pile-up using and identifying himself with our C21HA call sign. We know that there are police stations, we know that tuning on the DX QRG can happen, we know that sometime there is interference on the frequency.
We know that sometime pirate stations are working. We know that there are fake spots in the clusters, using invalid own callsign (like HA5DX, but we know the IP address). We know that very strong station continuously making QRM on our QRG and/or in the pile-up window. However, this cheeky, insolent attitude of this morning surpass every imagination. No words to classify this person. It is not simple annoying. It is fare beyond the rude, impolite behaviour. It will make lots of stations disappointed, as they may be changed reports with this pirate station. We are sorry about it. Is there anything further down? We spent a lots of our money to make other hams happy putting the C2, Nauru into their log. Whos (bussiness)interest has been disturbed by coming here to this remote Island?
That could help you to indentify the real C21HA: we always working with high speed CW, (35 wpm or more) on the higher bands, with 50 wpm rprt and TU. It may be helps.