A more thorough explanation:

Definition: To contaminate, taint with crime, or make liable in the seizure of contraband.

Examples:

• The virus infected the entire network.
• One part of the city has long been infected with illegal drug-dealing.
• Claiming that the single package of marijuana had infected the ship, the Coast Guard seized the entire vessel.

The first example shows how a virus can infect a computer network, spreading from one computer to another and causing harm. The second example illustrates how a particular area of a city can be infected with illegal activity, such as drug-dealing, which can have negative consequences for the community. The third example demonstrates how a single package of contraband can infect an entire ship, making it liable for seizure by authorities.