Under the USA Patriot Act, the significant change was the government's ability to monitor citizens' e-mails without a warrant. The act expanded the government's surveillance capabilities in an effort to combat terrorism, allowing law enforcement agencies greater access to digital communications and records.
The creation of the Department of Homeland Security was not a result of the Patriot Act but rather a separate initiative following the September 11 attacks. The act does not provide for the ability to search homes without a warrant or grant the right of prisoners of war to sue for their rights in U.S. courts.