填空题 Many privacy-protection Web sites work by inserting themselves as 1 and masking the Internet addresses of users" computers. If a user in a country with 2 goes to a privacy-protection site, that site becomes a shell that can be used to explore the Web. If the user types in the address of 3 , the government will see the user"s destination as the privacy-protection site that is the intermediary. So while a user 4 at the Safe Web site, for example, the site has an embedded frame that gives 5 .
But when governments are alerted, they can 6 the privacy-protection sites. In March, for example, 7 a number of such sites, including Safe Web.
Anonymizer combats such controls by changing 8 and cycling through domain every few months. (Its users 9 telling them the new names and addresses. )
"The names are 10 and not suspicious," said Mr. Cottrell, Anonymizer"s president. " 11 is that they are not very fast. When we 12 , it takes them a long time to block. "
But the governments 13 catch up, so privacy-protection companies must develop 14 to bypass the blocking technology. To control Web access, governments need to collect 15 . To Counter the governments, privacy- protection service must 16 .
In March, Safe Web 17 by releasing Triangle Boy software. With Triangle Boy, Mr. Hsu devised a system in which users around the world can 18 that allows their computers—and their Internet protocol addresses—to be used as conduits for sites that would 19 . Triangle Boy presents a problem for blocking programs, which have to try to 20 because the information is no longer stored on central servers.