A Brief History of Cybercrime and Cyberwarfare - The Technical and Social History of Software Engineering - page 400

Deaf and hard of hearing citizens would also be affected because the EMP
would no doubt destroy cochlear implants and hearing aids.
Email Address Harvesting
In today's world, email addresses are valuable commodities that are bought and
sold on a daily basis. In many cases, these lists are available from reputable com-
panies and often target either specific industries or specific kinds of jobs such as
executives or technical officers. How are these valuable addresses obtained?
In 2003, laws were passed in Australia and the United States that prohibit some
kinds of email harvesting, but there are still a number of legal ways available.
There are several ways of obtaining email addresses, and they vary in their eth-
ics and legality. One way is to use a harvesting bot or spider that searches public
sources of email addresses such as Usenet lists and internet forums. These email
addresses are then collected and added to lists, sometimes collated by industry or
type. This form of harvesting from public data is legal.
More unsavory forms of email harvesting include attacks on specific directories
and websites. A clever way of gathering email addresses is to use lists of common
names and then methodically try each name with a specific site. Suppose you have
an email address that is something like [e-mail] . Once the server
“privatemail” is identified, a harvesting tool would then send dummy emails to the
site to see which email addresses are accepted.
For example, the harvesting tool might go through the alphabet and send email
messages to “AJones,” “BJones,” “CJones,” “DJones,” and so on. If any are ac-
cepted, the valid addresses are added to a list and go to market. The same tool
might have a list of hundreds of common names and try things like “Arthur,”
“Betty,” “Charles,” “David,” “Emily,” and so on to see how many work. This
method now seems to be illegal.
A very common and legal method for harvesting email addresses is used daily
by thousands of companies. The companies simply offer a free trial, a free ser-
vice, or something else that might be useful and require that anyone who requests
it must provide an email address.
Long before the arrival of computers, some companies such as magazines and
consumer products would sell customer address lists. Address harvesting is merely
a continuation of an idea that is hundreds of years old.
There are a number of countermeasures to reduce the incidence of email ad-
dress harvesting.