A more thorough explanation:

The CAN-SPAM Act of 2003 is a law that regulates commercial email messages. Section 7(g) of the Act allows "internet access service" providers to sue spammers in federal court for violating certain requirements of the Act. An "internet access service" provider is a company that provides internet access to customers.

To bring a lawsuit, the internet access service provider must show that it has been harmed by the spam email in one of the following ways:

1. The spam email contains false or misleading information.
2. The spammer used a prohibited spamming technique.
3. The spam email contains sexually explicit material that does not comply with legal requirements.
4. The spam email has a deceptive subject line or does not provide an effective way to opt-out of receiving future emails.

For example, if a spam email contains false information that causes the internet access service provider's customers to lose money, the provider can sue the spammer for damages.

However, courts have interpreted the definition of an "internet access service" provider narrowly, and the provider must show actual harm from specific spam messages to bring a lawsuit. This can be difficult to prove in practice.