The copyright info. that I quoted on page 5 of this thread was included in my Keepsake Quilting Gold Club membership package, so anyone who disagrees with it could discuss it with Keepsake Quilting.
My theory is that if you do not buy/use a pattern, but copy all or part of a quilt or kit from a magazine or catalog, it would be very difficult for anyone to prove that you did that and hard to imagine that anyone would bother to try. Frankly, I don't worry about it because I don't sell quilts or patterns, but if I were selling quilts, I would want to stay within the law.