A bit of a nitpick, but the Hackernews post history and comments are publicly available. Most of, if not all, privacy law treats public data differently.

Now the majority of Facebook data, which is visible only to a selected group of individuals, can not contradict privacy laws of a country. Despite whatever agreement you signed. Law trumps user agreements.

As an extreme example I can sign that I give you the right to kill me, but if you do that you have still committed pre-meditated homicide. So it does not matter what Facebook made you sign it is likely they committed (and still do) a crime in most European countries. For the U.S. the waters appear extremely blurry from what I understand... But I can not offer an opinion. If there is a lawyer/ privacy expert to pitch in this discussion that would be nice.

> I can sign that I give you the right to kill me, but if you do that you have still committed pre-meditated homicide

This sounds as if nobody can agree to voluntarily take part in a potentially fatal experiment, like testing a potent medicine or be a test pilot. I believe legal provisions exist here.

That depends on the law in each individual legal region (most probably country). For example, I believe Euthanasia is legal in some European countries.

Even the opposite can be true. Life saving medication may be illegal in one country but another provides it without restriction.

Kind of sums up my reply. Generally, if you know or there is enough suspicion the cure is going to harm or kill one and euthanasia is out of the picture then you are liable. That's why the whole process exists about medical trials. One nice window here is that you can in general experiment on yourself (people have and are doing that). Depends on the framework, but good point.

Anyways, my point here is you can not override law (or you shouldn't be able to).

Absolutety.

At least in the UK you can’t sign away your health and safety rights. Even if the job is dangerous the employer still has a duty of care.

Having said this there are some job roles that are excluded from specific parts of the legislation due to their unique nature (e.g. the Army)

If it mattered to me, was necessary, and i was in the right legally, then I would need to.

Each country has its own laws covering this situation.

Giving someone personal information still restricts them legally irrespective of what they think i've consented to or their own definition of consent. The legal system has its own opinion.