That web site was absolutely hilarious! So comprehensive... I can imagine that the occasional person would be convinced, but it is littered with humour and there are many (presumably deliberate) subtle clues which point to it being a joke and also pointing out that it is utterly impossible, aside from being unspeakably cruel. The level of detail he goes into and the amount of technical correctness (apart from the apparently deliberate flaws) is so impressive. I think the only piece of humour I didn't appreciate was the use of a shoe horn to get the kitten inside the containers, it was a bit too silly. I absolutely loved the feedback page, especially the people discussing the different shapes their cats were in... "I tried to make a rhomboid cat, but it turned into a parallelogram... perhaps I could salvage it and produce a trapezoid shaped cat..." well, by that stage it wasn't making much sense, but the vivid descriptions and general absurdities were hilarious.
Yes, we would get upset if people spoke about snakes like that, but then again, they do it all the time, it isn't unusual for people to publicly boast about killing or torturing reptiles and we survive. This site gives so many clear clues that it's a big joke, it's all in good fun unless you're silly enough to get upset too quickly to notice. The vast majority of cat keepers are eco-terrorists anyway, so don't loose too much sleep if they get a little upset
I've seen spam emails going around trying to collect funds to stop the bonsai kitten movements... I can't tell whether they are serious or just trying to help the Nigerian economy, but always assumed the latter.
If cats have nine lives, why do I only ever need to kill them once?