Which post-9/11 law significantly enhanced government surveillance and required banks to identify sources of certain funds?

The USA Patriot Act is the post-9/11 law that significantly enhanced government surveillance capabilities and imposed requirements on financial institutions, including the obligation for banks to identify the sources of certain funds. This legislation was a direct response to the terrorist attacks on September 11, 2001, and aimed at expanding the government's ability to prevent and respond to terrorism.

One of the critical components of the USA Patriot Act is its provisions for surveillance, allowing law enforcement to access various forms of communication and records that would help in tracking and capturing potential terrorist threats. Additionally, the Act included measures that required financial institutions to conduct more rigorous due diligence to prevent money laundering and to verify where funds come from, particularly those that could be associated with terrorist activities.

In contrast, other laws mentioned do not possess the same level of surveillance enhancements or financial institution requirements that are central to the USA Patriot Act. For instance, the Anti-terrorism and Effective Death Penalty Act largely focused on legal penalties for terrorism-related activities but did not include significant surveillance or financial measures. The USA Freedom Act aimed to reform some aspects of the surveillance practices established by the USA Patriot Act but does not enhance them further. Finally, the Department of Homeland Security Act was more about establishing the Department itself and