Overview
From the beginning of the Internet (the ARPANET), sending of junk email has been prohibited, enforced by the Terms of Service/Acceptable Use Policy (ToS/AUP) of internet service providers (ISPs) and peer pressure. Even with a thousand users junk email for advertising is not tenable, and with a million users it is not only impractical, but also expensive. It is estimated that spam cost businesses on the order of $100 billion in 2007. As the scale of the spam problem has grown, ISPs and the public have turned to government for relief from spam, which has failed to materialize.
Read more about this topic: Email Spam