The No. 10 spot in our countdown goes to Wyndham Hotels. All that technical mumbo-jumbo designed to protect credit card numbers was apparently not worthwhile. So when credit card data was stored in plain text, Wyndham might've been the only ones surprised when cyber thieves broke in and stole some of them. With faith in the premise that lightning never strikes twice, Wyndham apparently decided it had paid its proverbial dues. But, guess what. Wyndham got hit three times in two years. More than 600,000 credit card numbers fell into the wrong hands, and some $10.5 billion in fraudulent transactions was reported, gaining the hotel chain some much-needed attention from the Federal Trade Commission.