Ever wondered why the legal drinking age in the US is 21? Here's a true and touching story:

Candy Lightner lost her 13-year-old daughter in 1980, killed by a drunk driver. She gathered a number of other mothers who had a similar story and founded Mothers Against Drunk Driving (MADD). In a few years they succeeded in pushing for some laws that prevent such tragedies, such as lowering the acceptable blood alcohol level and raising the legal drinking age to 21.

What Candy Lightner and MADD have done is an example of .