On 21st May 2009, which marks the 22nd anniversary of 'Operation Spectrum', a group of concerned Singaporeans demonstrated against the treatment of the detainees who were detained without trial under the ISA.
On May 21st 1987, 22 young social workers, lawyers, businessmen, theatre practitioners and other professionals were detained without trial under the internal security law and accused of "being members of a dangerous Marxist conspiracy bent on subverting the PAP ruled government by force, and replacing it with a Marxist state." A second wave of arrests took place on June 20th the same year.
emnews. (December 04, 2014). Remembering 22 Singaporean Victims of ISA. Retrieved February 18, 2020, from EngageMedia Web site: https://www.engagemedia.org/Members/emnews/videos/remembering-22-singapore-victims-of-isa.