Humans should only be granted the ability to go on their own terms. This would be good if a person had a debilitating medical issue that is terminal and all medical repair methods have been exhausted. An example scenario where this can be used would be if the person is in a severe, unrecoverable state. If they cannot wage their own opinion on being put down (that's basically what it is), their will or family should be consulted next. I find keeping people in a vegetative state is a waste of money and downright wrong.
Euthanasia, primarily, allows those in suffering with no hope of recovery to die on their own terms and by their own choice. It is simple to control it in order to prevent unlawful deaths-It should only be done with the express permission of the person; either through direct confirmation, a will (in case of paralysis/coma) or a third-party guarantee. Euthanasia is not a means by which to eliminate those weaker and in suffering, but rather as a way to permit those in pain and who've lost hope to end their lives in peace
Hello, I am John Q. Retiree, and the person euthanasia would be marketed to the most. I say "No."
Abuse A: I happen to have made a bit of money, and have a few unscrupulous heirs. Before I know it, one's a guardian, and I'm carted off to be blammed.
Abuse B: I didn't make much, and I've been injured. I'm covered under State medical insurance. Unfortunately, a bureaucrat is on my case, and says that I can't put any more in, so it's cheaper to kill me, so they can continue making welfare checks, apparently. Ka-dead.
Abuse C: I am an outspoken opponent of the ruling party. After my media gets shut down, I'm quietly euthanized as per a decision made a closed meeting, the State assuming my right to euthanasia.
In short, abuses, abuses everywhere.