A couple of random thoughts...

By default in the U.S., authors own whatever they write unless they have specifically agreed to something that says otherwise (e.g. in a Terms of Service agreement or the like). So while someone may claim a different agreement, unless they can prove you agreed to something other than your retention of ownership of your own words, they are *yours* and yours alone to do with as you please.

Now, in the case of BT, they claim something different, yet the registration when a new user signs up makes no mention of this claim, nor does their TOS (which I couldn't find, since the bottom link to their terms of service is still broken!). So, even though BT claims a Creative Commons license for their work, it's unlikely that it would be found to be legally binding to its members, since its members are never asked to agree to such a license when they signed up to the forums in the first place.

Having said that, the CC license BT is claiming says you can go ahead and copy and redistribute anything you find on their site as long as attribution is given (e.g., "Originally posted to BrainTalk by so-and-so person."), it's for non-commercial use (NT is non-commercial), and you can't alter or build upon the post you're copying (basically, you need to copy it whole).

So, having said that, I'd say that for limited amounts of copying, especially that which is meant to educate or inform other members, I'd say you're welcomed to do so. If it is of another member's work, though, I would definitely get that member's permission first, when possible, since that would just be common courtesy to do so.

John