[4] The Act defines terrorism as: The definition states that "advocacy, protest, dissent, stoppage of work, industrial or mass action, and other similar exercises of civil and political rights" shall not be considered as terrorist acts only if they "are not intended to cause death or serious physical harm to a person, to endanger a person's life, or to create a serious risk to public safety."

[9][10] During the colonial era, forces fighting for Filipino independence, such as those under Diego Silang, Andres Bonifacio, Emilio Aguinaldo, and Macario Sakay were intentionally labeled "insurrectos" and "bandits" in order to de-legitimize and downplay their cause.

[13][14][15]: "43"  A 1968 Philippine senate investigation into the Jabidah massacre, in which Muslim recruits were supposedly massacred in Corregidor to prevent them from blowing the cover on a botched Military operation resulted in the rise of multiple secessionist movements in the Muslim-majority areas in western Mindanao Island, including the Muslim Independence Movement, the Bangsamoro Liberation Organization.

[19] In northern Luzon, the murder of Macli-ing Dulag for his opposition to the Marcos administration's Chico River Dam project became a rallying cry which inspired the formation of militant groups such as the Cordillera People's Liberation Army (CPLA).

[50] Proponents of the law have cited the siege of Marawi in 2017 as well as criminal activities from the Islamic State-linked Abu Sayyaf group, New People's Army Communist Rebels, and other supposed emerging threats to peace and public safety.

[4] In 2021, the Olongapo Regional Trial Court acquitted Japer Gurung and Junior Ramos, Indigenous Aeta residents of Zamboanga, in the first known anti-terror law case, ruling that the accusations were the result of mistaken identities.

[68] In November 2023, the prosecutor's office in Santa Rosa City in Laguna rejected a complaint against human rights worker Hailey Pecayo and other activists over the alleged violation of the anti-terror law.

[69] In the same month, a prosecutor in Antipolo, Rizal, dismissed anti-terror law charges against human rights activists Kenneth Rementilla and Jasmine Rubia.

[70] In November 2023, Windel Bolinget and three other Indigenous rights workers of the Cordillera People's Alliance filed a case before the Baguio Regional Trial Court challenging their designation as terrorists by the Anti-Terrorism Council.

[71] On July 15, 2020, 50 members of the United States Congress urged Ambassador Jose Manuel Romualdez to request the Government of the Philippines to consider repealing the "oppressive and unnecessary legislation".

"[76]The Southeast Asia office of Greenpeace urged the repeal of the Anti-Terrorism Act of 2020 due to its "sweeping definition of terrorism" which it said could be abused to stifle dissent.

[84] On July 2, 2020, the Bangsamoro Parliament passed a resolution urging President Rodrigo Duterte to veto the anti-terrorism bill, arguing that it would lead to abuses and would unfairly target Muslim Filipinos who have historically faced religious discrimination.

[87] More than 1,000 students and human rights activists gathered inside the UP Diliman campus on June 12, 2020, coinciding on 122nd Independence Day from Spanish colonial rule, dubbed it as "Grand Mañanita".

[88] They called for the government to "junk" the proposed bill stating fears that it would curtail basic human rights and freedom of speech and dissent.

The rally was held despite a government ban on mass gatherings under the general community quarantine in Metro Manila and other parts of the country because of the pandemic.

"[92] The Philippine Council of Evangelical Churches had likewise expressed reservations about the bill, saying "We firmly believe this Act imperils the rights of Filipinos and sense of dignity which, having its origin in God, our laws are called to uphold and protect."

The PCEC specifically cited "vague definitions of terrorism, and the extended period of warrantless detention, which opens the way to serious abuses of a person's rights and dignity" as reasons for concern.

[93] The National Federation of Peasant Women (Amihan) have said that the rising cases of red-tagging in the country confirm the prevalent criticisms against the controversial legislation.

[citation needed] Celebrities, including former Miss Universe titlists Gloria Diaz, Pia Wurtzbach, and Catriona Gray, voiced their opposition to the bill.

[103] Seven protesters from University of the Philippines, who were condemning the controversial anti-terror bill, and one bystander were arrested in Cebu City in June 2020 for alleged violations of general community quarantine guidelines.

[109] The Facebook accounts later targeted residents in Metro Manila, Iloilo, Dumaguete, Cagayan de Oro City, and other areas where protests against the bill were held.