In the landmark case of Chng Suan Tze v. Minister for Home Affairs (1988), the Court of Appeal sought to impose legal limits on the power of preventive detention by requiring the Government to adduce objective facts which justified the President's satisfaction.

In 1989, he commented that he "could not imagine then that the time would come when the power of detention, carefully and deliberately interlocked with Article 149 of the Constitution, would be used against political opponents, welfare workers and others dedicated to nonviolent, peaceful activities".

In its manifesto for the 2011 general election, the Workers' Party said that specific anti-terrorism and anti-espionage laws, which allow arrests and detention without trial only under strict conditions, should be enacted to replace the ISA.

(3) If, in respect of any proceedings whether instituted before or after 27th January 1989, any question arises in any court as to the validity of any decision made or act done in pursuance of any power conferred upon the President or the Minister by any law referred to in this Article, such question shall be determined in accordance with the provisions of any law as may be enacted by Parliament for this purpose; and nothing in Article 93 shall invalidate any law enacted pursuant to this clause.To satisfy the requirements of Article 149(1), the preamble to the Malaysian ISA, which has been retained in Singapore's ISA, contains the following recital: Whereas action has been taken by a substantial body of persons to cause a substantial number of citizens to fear organised violence against persons and property: And Whereas action has been taken and threatened by a substantial body of persons which is prejudicial to the security of Malaya: And Whereas Parliament considers if necessary to stop or prevent that action:

[25] In addition, if the Minister considers it to be in the national interest to do, he may prohibit the "manufacture, sale, use, wearing, display or possession of any flag, banner, badge, emblem, device, uniform or distinctive dress or any part thereof".

Prior to 1988, the Singapore case of Lee Mau Seng v. Minister for Home Affairs (1971)[55] was authority for the application of the subjective discretion test for judicial review of executive power exercised under the ISA.

Additionally, Teh Cheng Poh v. Public Prosecutor (1978)[71] decided by the Privy Council on appeal from Malaysia, was referred to by the Court in support of the objective test.

Section 8B(1) of the amended ISA provides that the law pertaining to the judicial review of decisions made by the President or the Minister was restored to the legal position applicable in Singapore on 13 July 1971, the date when Lee Mau Seng was decided.

In Teo Soh Lung, the Court of Appeal held that it was not necessary for it to decide if the subjective test in Lee Mau Seng precluded judicial review in the case.

[96] In a lecture to law students in 2010, Chief Justice Chan Sek Keong commented that, in general, "ouster clauses may be inconsistent with Article 93 of the Constitution, which vests the judicial power of Singapore in the Supreme Court", though he expressed no concluded opinion on the matter.

[111] In 1989, Law Minister S. Jayakumar argued in Parliament that the amendments were needed because the courts would effectively be responsible for national security matters if judicial review was permitted.

[112] Tham Chee Ho contends that, based on the objective test set out in Chng Suan Tze, the fear that the courts will take over responsibility for national security matters is misplaced.

He distinguishes the objective test applied in Chng Suan Tze from the situation mentioned by Jayakumar, since the court is only interested in whether there is a national security issue involved.

One example of a non-legal institutional check is the requirement under the Constitution and the ISA for an advisory board to hear detainees' representations and recommend to the President whether a detention order should be terminated.

[115] Similarly, in Chng Suan Tze, the Court of Appeal rejected the view that the executive's accountability to Parliament is a sufficient safeguard against the arbitrary exercise of power.

Chua argues that in Teo Soh Lung the Court of Appeal should have considered whether there were sufficient safeguards for the protection of detainees after the curtailment of judicial review through constitutional and legislative amendments.

[129] According to The Sunday Times of 28 October 1956, 234 people, including trade union leaders Lim Chin Siong, James Puthucheary and C. V. Devan Nair, were detained under the PPSO as suspected Communist subversives.

[132] He was subsequently held for 32 years pursuant to the ISA, the last nine of which under forms of house arrest and civil rights restrictions, including confinement on the island of Sentosa.

He was released on 21 February 2010,[145] but rearrested in September 2012 and detained under the ISA the following month for planning to resume jihadist terrorism against foreign military operations abroad, including leaving Singapore – illegally, if necessary – to do so.

[146] In September 2013, the Singapore media reported that Asyrani Hussaini had been detained in March that year and was the fifth Singaporean to have been influenced by radical ideology he had read online.

Three Singaporean former JI members had their restriction orders lifted; they were Jahpar Osman and Samad Subari, and Abdul Majid Kunji Mohamad who had trained with the MILF.

[150][151] In March 2021, the ISD confirmed it had detained 20-year old national serviceman Amirull Ali under the Internal Security Act for plotting to attack three Jewish worshippers at the Maghain Aboth Synagogue in solidarity for the Palestinians.

[152][153][154] On 24 January 2024, the ISD issued a restriction order under the Internal Security Act against a 16-year old Chinese Singaporean youth who had aspired to carry out overseas attacks against African Americans, Arabs, and LGBTQ+ individuals in North America and Europe.

[171] The ISA places a duty on any person, any office-bearer of an association, or any responsible member or agent of an organization who receives a subversive document to deliver it to a police officer without delay.

[172] The Home Affairs Minister may, under Chapter IV of Part II of the ISA, order that any entertainment or exhibition be closed if satisfied if it "is or is likely to be in any way detrimental to the national interest".

The board of managers or governors of an affected school or educational institution can lodge an objection against an order with the President, whose decision on the matter is final and may not be questioned in any court.

If the Commissioner employs such steps, he must take precautions (including displaying prominent warning notices) that he considers reasonably necessary to prevent accidental entry into the place.

If the measures are taken in a place other than on, under or within the perimeter fence, the Commissioner must take precautions – including displaying prominent warning signs – to ensure that people do not accidentally enter the area.

[221] Police officers are permitted to use reasonable force when effecting the taking of possession,[222] and the Minister can require the owner or occupier of the land or building to provide information relating to it.

[235] However, the Privy Council declined to allow this submission as it involved the presentation of a case completely different from the one that the appellant was required to meet during his trial and the appeal before the Federal Court.