hmmm. Everything seems quite civil at the moment. My ten pence worth.
I have both an airzound horn and a helmet camera...I guess that makes me a loser with no life, but I can deal with that
In regard to the airzound, I have seen some cycling videos where people seem to use it and hold it down for no real reason/for a long time after the incident (just to make a point). I will use it to warn people of my presence, such as if someone does pull out on me, pulls into me, overtakes too close and so on. I will also give light warning taps to stop incidents from even happening, and just to let people know I am there. I will 'tell people off' by giving a short blast if something has scared the bejesus out of me (such as a really close overtake), however, I generally wouldn't just hold the horn down for ages.
I don't feel that using a horn should cause offence, though would accept if I held it down for a minute after something it might do.
Now, with the camera. I first wanted one just because I thought they were a cool bit of kit. When I bought it it was because I had nearly been wiped out by a bus driver and got fed up when the police wouldn't do anything about it. I don't wear it every time I go on the bike. I just use it on my commute/during heavy traffic/rush hour. Basically, at times when I feel there is an increased risk of poor road behaviour (everyone in a rush).
Now, been a few comments about how isn't it weird that a cyclist goes out filming with a camera? I know car drivers that do the same thing so it isn't that weird.
Not sure I've really said anything of any benefit, but it's wasted a couple minutes while my dinner cooked!!