Mirror sites host exact copies of another Internet site.
"Cut us down and the stronger we become," a message on WikiLeaks' Twitter page read Sunday.
The United States is pressuring Switzerland not to offer a haven to WikiLeaks founder Julian Assange. Responding to indications that Assange and WikiLeaks may seek refuge in Switzerland, U.S. Ambassador to Switzerland Donald Beyer Jr. told the magazine NZZ am Sonntag the Swiss "should very carefully consider whether to provide shelter to someone who is on the run from the law."
Swiss postal officials said they were reviewing their relationship with Assange, subject to proof that he has Swiss residency, is a property-owner or conducts business in the country, the Times said Monday.
Since releasing classified U.S. State Department cables a week ago, from a cache of more than 250,000 documents it obtained, WikiLeaks has been the target of cyberattacks. Last week, it was dropped by companies such as PayPal, an online payment service that had accepted donations for the WikiLeaks Web site, Amazon, which rented it server space, and EveryDNS.net, which provided domain name service.
The organization Anonymous, an informal but intensive group of hackers and activists, called on its supporters Sunday to attack sites of companies that aren't supporting WikiLeaks and to spread the leaked material online.