If there is one thing I have learned in all the years I've been doing genealogy it's this: it's all about sharing. I can't count the number of times that some generous soul has furthered my research with a look-up, or a scanned document, or just an email saying I have the same ancestor, so let's share information! Genealogists are generous souls. They love to share their knowledge and pass it along.
That being said, credit should be given when using another's work. If you want to use something that I have created, send me an email and ask my permission. More than likely I will give you that permission as long as you agree to give me credit for my work. If I happen to post a photo of an ancestor that also happens to be your ancestor, send me an email and ask me for a scan. I understand the excitement of coming across an unknown photograph of an ancestor you may never have seen before. I have felt that same excitement. Asking before you use it just builds goodwill. I have come across a number of trees on Ancestry that have included pictures that I posted on FindaGrave. Actually they were screenshots of the whole page. Not once have a I received an email from any of these people asking for permission or even for more information, although my email address is provided. This is just laziness and poor research coupled with bad morality.
Since the title of my post is Paying It Forward , I guess I meant that to have a dual meaning. Give credit where it's due and I'm more than happy to help you in your research. Take my information without asking, and you can pretty much forget my help with anything. Use my intellectual property as your own on a continual basis, and I will take action. That is my rant for the day.