Peter, a malicious hacker, obtains e-mail addresses by harvesting them from postings, blogs, DNS listings, and Web pages. He then sends large number of unsolicited commercial e-mail (UCE) messages…

Email spoofing involves forging the sender address or message headers to impersonate another identity, which is not described in the scenario.

Email spam (UCE - Unsolicited Commercial Email) is characterized by harvesting recipient addresses from public sources such as websites, blogs, and DNS records, then distributing bulk commercial messages to those addresses without consent. Peter's behavior - automated harvesting followed by mass UCE distribution - precisely matches this definition and is the conduct regulated under laws like the U.S. CAN-SPAM Act.

Email bombing means flooding a single target address or mail server with an enormous volume of messages to cause denial of service, which is distinct from sending UCE to many different harvested addresses.

An email storm is an uncontrolled cascade of automated reply-all messages that overwhelms a mail system, not a deliberate bulk commercial mailing campaign by a spammer.