From the Postcrossing.com website blog:
Butterflies are crossing the World - On the 10th of May it's International World Lupus Day, which has the goal of bringing more awareness over this chronic disease that affects over 5 million people worldwide
Send a butterfly postcard to support Lupus sufferers - http://www.postcrossing.com/blog
Please note: I am a member of Postcrossing and this post is genuine and not a gimmick.