Short question: should we provide links to the answer, or copy external content into our answer?
Long question: In response to this question, I provided a link to an external blog (of which I'm not the owner) which provides an exhaustive listing of the running terms and acronyms which the original questioner requested.
A comment to my answer suggested that since links can grow stale, I should have provided more than a link, but also included a summary of the content. While I agree that this works for some content (see the question about the Ironman distances, where I gave a short summary and also a link to a detailed explanation in Wikipedia), I don't know that this is appropriate/possible for some kinds of content - specifically, a long list of definitions.
My concern is that if I cut and paste a large chunk of content from some other site, I open myself, and StackExchange to copyright infringement liability.
Is there a "tipping point" for how much external content should be copied into answers?