Read the following sentence: A woman without her man is nothing. My guess is that if you're a woman it pissed you off because you read it in the following way: "A woman, without her man, is nothing". If, however, you made just a small change in punctuation it could be read this way: "A woman: without her, man is nothing."
My point is this: Sometimes a small change can have a huge impact. In the above case, the meaning was fundamentally altered.
Now consider the issue of organ donations. It is estimated that in America over 90,000 people are currently on waiting lists. Many of those individuals will, unfortunately, die on a waiting list due to a shortage of available organ donors.
It need not be this way. In Germany, only 12% of the population has agreed to donate an organ (in the event they die unexpectedly). In Austria, the percentage is a staggering 99%. The difference? In Germany, people must explicitly give their consent to donate an organ by opting in on a state-provided form. In Austria, people must explicitly opt out. In other words, in Austria, people are assumed to consent to organ donation but are free to opt out if they are uncomfortable with the idea.
In a perfect world, it shouldn't matter what wording the state puts on a form. If people want to donate an organ they are free to do so under either policy. Austria, though, has learned that a small change in language can lead to a huge change — one which saves many lives.
If other states and countries want to do the same maybe they should start by unlearning their "opt in" clauses.