Now--what's your call on this: a member contacts your association saying they've developed an app that includes content created by your association (say a Twitter or blog feed). They intend to charge for the app. Do you grant permission or not? Hypothetically-speaking only, of course ;)
My two cents, and I am not a lawyer, don't play one on TV and didn't stay at a Holiday Inn Express last night...
That is your content. It isn't public domain. No one should be able to profit from something that your association created (albeit it was most likely volunteers donating the time and knowledge). You wouldn't let your competing association do it, so why a member?
Now, if they had extra content or some new technology to offer that piggybacks off what your association created, I would try to license it or purchase it from the member and launch it under the association's umbrella. That way the member gets the money they were looking for and the association gets another product.