The internet spoofs follow an extraordinary crackdown on anything purported to spread leftist ideology, amid sweeping fears of a resurgence of the Indonesian Communist Party (PKI). Banner in Yogyakarta reading: "Thrash and wipe out communism from a united Indonesia". Credit:Amilia Rosa This month four activists in North Maluku were arrested over red t-shirts featuring a motif of a hammer and sickle floating in a cup of coffee. The acronym on the coffee cup was PKI, which purportedly stood for Pecinta Kopi Indonesia (Indonesian coffee lovers). In Yogyakarta, police broke up a screening of a documentary on a political prisoner who was imprisoned without trial on Buru Island for 10 years for being a member of a leftist organisation. Ironically the event coincided with World Press Freedom Day.

Any activity which propagates communism, Marxism and Leninism is banned in Indonesia under a 1966 decree which dissolved the PKI. Anyone violating this ban can be sentenced to a maximum 12 years in jail. However, recent fears of a communist revival and the ensuing crackdown have been sparked by last month's historic symposium on the 1965-66 massacre of at least half a million people suspected of leftist leanings. This was the first time the Indonesian Government has ever endorsed a forum to discuss one of the darkest chapters in Indonesia's history. Chief Security Minister Luhut Panjaitan subsequently announced the government would form a team to excavate mass graves.

Australian National University Professor Ariel Heryanto– the only speaker at the symposium from outside Indonesia – attributes the paranoia about a resurgence of communism to a number of factors. One, he says, is genuine anxiety about the possibility that those responsible for the massacre could be indicted for crimes against humanity. Another is the angry and hostile response to the symposium, which acknowledged the plight of the victims of the 1965 massacre and sought some form of reconciliation. And third, he suggests a ploy on the part of disenchanted segments within the political elite to destabilise the government. Asked if he was expecting the backlash, Professor Heryanto said: "Definitely, we are witnessing it now".

Earlier this month rumours swept Indonesia that the PKI planned to stage a reunion in Yogyakarta on May 9. The day before the phantom reunion a group of anti-communist activists calling themselves the Anti Communist Red White Elements, issued a statement warning that communist ideology was "still an insidious problem that is growing in Indonesia". It urged the government to retain the ban on communist teachings, reaffirm its decision not to apologise to the so-called victims of the anti-communist purge and take action against any activities associated with the PKI and its derivatives. Banners were erected around Yogyakarta with slogans such as: "Save Indonesian youth from the latent danger of communism". Yogyakarta deputy police chief Abdul Hasyim Gani told Fairfax Media he still didn't know why Yogyakarta had been selected as the location for the rumoured PKI reunion. "We also don't know the reason behind it," he said.

"The police cybercrime division detected the source of the broadcast was from Vietnam. But that has proven it was just a rumour. There's no proof that PKI is making a comeback." Meanwhile, publishing company Ultimus said a bookshop in Yogyakarta was told it could not display a book about the history of 1965. "The book content was said to twist PKI history," said Ultimus editor Bilven Rivaldo. "But that's not true. There is no official version of history. There are different points of view of history. Such a thing [confiscating leftist books] is like going back to the New Order era. If anyone tries to defy the government they get shut down." President Joko Widodo, who initially ordered the military and police to uphold the law against any spread of communist teaching, recently warned them not to be excessive. "Democracy is the substance of the state. So the police, as well as the military, went too far with their sweeping operations," the Jakarta Post quoted Cabinet secretary Pramono Anung as saying on Friday.

A scathing editorial in Tempo magazine this week said a campaign that raised the spectre of a communist revival always seemed to happen when someone questioned the state's silence over the victims of the 1965 pogrom or there was friction among the political elite. "Communism is dead and buried and will never return – except in the eyes of those who continue to preserve the fear of an ideological ghost." With Amilia Rosa and Karuni Rompies​ Follow Jewel Topsfield on Facebook Follow Fairfax Foreign on Twitter