The Internet is extremely powerful and flexible because of the way it works, although people are frequently surprised by how it works. When information (like a bit of text, a picture, or an email) is sent across the network, the sending computer puts the information into a packet, or series of packets, and hands them to a computer closer to the destination computer. In the end, this process resembles taking a postcard and handing it to someone else to be delivered. The person receiving the postcard looks at the address and hands it to someone else who is a little bit closer to the addressee. Computer networks are somewhat more formal and have a better sense (usually) of who the next-closest computer is, but the process is essentially the same. It is common for seventeen or so computers to handle a packet before it reaches its destination. The text of the postcard, or content of the packet, is available for anyone to read, if they so choose. Most computers do not examine the...