The other way Sarah can get caught is if someone can determine her identity from information provided by his or her Web browsers or email programs. Every computer connected to the Internet has — or shares — an address called an
IP address, which consists of a series of four numbers from zero to 255 separated by dots (for example, 213.24.124.38). When Sarah uses her Web browser to make a comment on the minister's blog, the IP address she was using is included on her post.