Hi Markus, thanks for the reply but I really was after video material. I hoped someone might have put together a few minutes-long demo with an explanatory voiceover or similar. I've been using my own and others' screenshots up until now; as awful as yours are, showing the problem in motion is much more effective.
Great letters though! Did you get a decent reply? I think I already know the answer...
I reckon the best way to deal with stuff like that nowadays is 'out' them via their own social media or their websites, if they have comments enabled.