Have you ever listened to a speaker present an idea that you thought you came up with first, and that speaker expresses the idea as his/her own?
I'm sure we've all had that experience.
I'm also sure that we've all expressed an idea we thought was our own only to realize that we learned that idea through a tweet, blog post, discussion, or book earlier in our lives.
Ideas spread like fire in real time and online, and frankly, it's difficult to figure out where an idea originated, and does it matter anyways?
As much as possible we should give credit where credit is due and acknowledge the individual, book, blog post, or conference where we first heard or learned of an idea. Crediting the source is a good, respectful practice.
We should also be less sensitive about our ideas since ideas will arise from multiple sources, and only when we make the time to tackle an idea with depth can we truly say that we own the idea--it's the work that makes a good idea a reality that matters.