for-phone-onlyfor-tablet-portrait-upfor-tablet-landscape-upfor-desktop-upfor-wide-desktop-up Reuters NowAmazon shares tumble after cloud warningPosted UPDATE! - Amazon signaled on Thursday its long lofty cloud growth would slow further as its business customers braced for turbulence and clamped down on spending, overshadowing the company's quarterly sales and profit that topped expectations. Fiona