What use is an F-call? The radio waves are open to all comers, licensed or not. That means that while you have to be licensed to use a particular frequency and that stiff penalties apply if you're not, there's nothing physically stopping anyone from using any frequency. I recently had a report from a fellow amateur who had a particularly unpleasant experience on-air. They were accosted by another station. Fortunately that amateur had a witness to the experience, so they didn't feel completely alone in the moment. It did stop them from being on-air until surrounded by friends. This discovery brought out other experiences from other amateurs, one told how another station was impersonating their callsign, and only being advised of this by other amateurs brought this to their attention. I've heard another station use my voice from a recording like the news, and transmit that on a local repeater, and I've heard other stations being abused and stories about abuse. Abuse will happen. Idiots are everywhere in society, lonely, sad people, or malicious, or both, or something else. Fortunately these incidents are not common, but they do occur. What should you do when this happens to you? Many and varied opinions exist. Sometimes it's not obvious that you're dealing with a station that's up to no good, but once you are, the best advice I've been given is to log the experience, attempt to get a recording of it, and report it to the ACMA. Don't engage the other station. Ignore it. In contests, when this might happen, I'm told that the best action is to treat the station as local noise and ignore it. If you have trouble hearing another station, time your calls to coincide with the interference, refer to it as QRN if at all. I know that this is simple to say from the comfort of my shack, but it's the best advice I have to share. If you have other comments about this, send me an email, vk6flab@wia.org.au. I'm Onno VK6FLAB