Why is everyone assuming that the "colonists" will die within days of arrival? I am willing to bet that there will be lots of volunteers for one-way missions to Mars (provided good chances of survival).

So most people don't mind sharing personal information with these "friends", but when it comes to sharing their email is where they draw the line? I would think it would be the reverse. Many people have my email address, very few of them know who I am dating or what I did last night.