Hackers have crippled one of the internet's biggest credit card processors, and tens of thousands of online merchants are losing business while the company struggles to recover.

Since last Wednesday, Authorize.Net has been relentlessly pounded by distributed denial of service, or DDoS, attacks. The massive, coordinated waves of internet traffic have repeatedly overwhelmed the company's servers. Authorize.Net's customers have had to improvise: Some are confirming their credit card orders over the phone, others have gone with little or no sales for nearly a week.
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With about 90,000 customers, Authorize.Net is one of the internet's best-known, most widely used credit card processing services, focusing mostly on smaller merchants.
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