听力原文：Email captures the essence of life at the close of the 20th century with an authority that few other products of digital technology can claim. Email, ultimately, is a fragile thing, easy to forge, easy to corrupt, easy to destroy. A few weeks ago, a co-worker of mine accidentally and irretrievably wiped out 1,500 of his own saved messages. For a person who conducts most of his life online, such a digital tragedy is akin to erasing part of his own memory. Suddenly, nothing is left. He has lost himself as well as his links with others. Which of the following is true, according to the passage?