The Internet is often called a global village, suggesting a huge but close-knit community that shares common values and experiences. The metaphor is misleading.
Many cultures coexist on the Internet and at times clash.
In its public spaces, people interact commercially and socially with strangers as well as with acquaintances and friends. The city is a more apt metaphor, with its suggestion of unlimited opportunities and myriad dangers. To steer clear of the most obviously offensive, dangerous or just boring neighborhoods, users can employ some mechanical filtering techniques that identify easily definable risks. One technique is to analyze the contents of on-line material. Thus, virus-detection software searches for code fragments that it knows are common in virus programs.