I'd agree with
NismoDrifts.
Igor may have more information about whether the site owns any information posted here, but generally, get permission from the members, and I guess you'd be all set.. and consult an attorney as necessary to check for any loopholes (and, not sure if the site is governed by US laws, international laws, or exactly how that works - it might even de determined by the nationality of each respective member).
So, Mr. T, you thinking about writing a book about one of AF's forums???