From Christopher de Bellaigue at The Guardian:
As the world’s pioneer, the Netherlands has also discovered that although legalising euthanasia might resolve one ethical conundrum, it opens a can of others – most importantly, where the limits of the practice should be drawn. In the past few years a small but influential group of academics and jurists have raised the alarm over what is generally referred to, a little archly, as the “slippery slope” – the idea that a measure introduced to provide relief to late-stage cancer patients has expanded to include people who might otherwise live for many years, from sufferers of muscle-wasting diseases such as multiple sclerosis to sexagenarians with dementia and even mentally ill young people. More.
Reality check: Exactly. Was there something else they wanted to know?
And once it is okay to kill one patient, it is okay to kill any of them.
See also: Fatal Flaws: A Canadian film chronicles the march of euthanasia