If you've read Robert Fulghum's All I Really Need to Know I Learned in Kindergarten, you know that genealogists have mastered one childhood lesson: how to share with others. When an Internet cousin asks for your research on Great-great-grandpa, you're happy to oblige. You might even post your ancestral discoveries online or write a book about them.

What you may not have learned in kindergarten is that sharing has limits. For example, the Denver Public Library <www.denver.lib.co.us> might not be pleased if you published one of its online photos in your family history. The author of Springfield County Founders would be similarly underwhelmed if you photocopied chapter seven for your family's entire California contingent. And Aunt Sue probably wouldn't consider it a personal favor if you submitted her GEDCOMs to GenCircles <www.gencircles.com> without first getting her OK.