The COMET program at http://meted.ucar.edu/ contains a number of images and other material that are directly applicable and of great use to the questions and answers at this site. However, I'm a bit leery of using such content because of their terms of use:
Subject to these Terms of Use and any Additional Terms imposed by a Third Party, the user is granted the right, without any fee or cost, to access, link to and use, publish, distribute, disseminate, transfer, or in any manner alter, modify, revise, crop, copy (an unlimited number of times), edit, digitize, and authorize such uses for third parties for any non-profit training, research, or educational purpose whatsoever and not for any direct or indirect commercial purpose or advantage."
Copyright to the questions and answers across the stack exchange network is transferred to the for-profit Stack Exchange, Inc., so that might preclude usage due to the "and not for any direct or indirect commercial purpose or advantage" clause. However, all of the SE content is licensed as cc-wiki (CC-BY_SA), so in a sense it is free. Moreover, this site, along with many other elements of the SE network, has education as one of its goals.
While I used the COMET program as the basis for this question, this question is not specific to that program. There are many other sites that allow free use of those sites' copyrighted material for educational purposes but explicitly disallow such use for commercial advantage.
Question: Is properly attributed use of COMET content (or from sites with similar terms of use / license agreements) allowed at earthscience.stackexchange.com, or is it illegal and something I should avoid doing?