The 2001 Patriot Act broadened the definition of who could be seen as a terrorist and expanded the government's power to detain, investigate, and prosecute suspected terrorists. Federal agencies can monitor Internet messages and tap phones, usually with a warrant from the FISA court. What legal concept supports the federal agencies' actions?

government surveillance

Explanation:

Based on the scenario being described within the question it can be said that the concept that best supports this would be government surveillance. This concept refers to the government's right towards gathering intelligence information for the prevention of crime, the protection of a process, person, group or object, or the investigation of crime. Stopping suspected terrorists falls under these categories.

answer; george herbert mead;