A new report suggests there is a growing terrorist threat in Indonesia from what are described as freelance terrorists - people operating outside groups such as Al Qaeda or Jemaah Islamiah (JI).
The report from the Australian Strategic Institute was compiled from in-depth interviews with 33 convicted terrorists in Indonesian prisons.
The report's author, former Australian government intelligence analyst Dr Carl Ungerer, has told the ABC's Lateline program that in many cases the prisons are acting as incubators.
Dr Ungerer says a group of hardcore jihadis are preparing to leave Indonesian jails over the next 18 months, and some of them say they will bomb Western targets.
"Several of the men we interviewed hold this view. One of them said to us directly that if he was released from prison today, he would bomb the US embassy tomorrow," he said.
These men say they no longer need the backing of a large terror organisation like the now defunct JI, which orchestrated the Bali bombing in 2002, killing more than 200 people including 88 Australians.
That operation took three months to plan, involved 20 people and cost about $40,000.
A growing number now call themselves freelance terrorists, willing to try smaller, more random attacks.
"We're no longer dealing with organisations or organisational hubs, we're dealing with individuals, some call them lone wolves, some call them freelancers," Dr Ungerer said.
"Nonetheless, individuals who will go out and simply conduct operations in groups of two or three, which is pretty much all it took to do the Marriott hotel bombing in 2009.
"It means that the threat is not going away, if anything, it's getting worse."
De-radicalisation immunity
Such attacks are already a growing scourge in Indonesia, and last year there were a series of book bombs.
Australia helps train Indonesia's counter-terrorism unit, which has arrested about 600 people in the past decade.
Based on the prison interviews, Dr Ungerer says the convicted terrorists fall into two groups.
The vast majority fought in specific on-going conflicts like Afghanistan or in local conflicts with Christians, such as in Ambon. This group, he says, is less likely to participate in indiscriminate bombings such as Bali.
But about 30 per cent now share Al Qaeda's view of global jihad against the West, and are seemingly immune to de-radicalisation programs.
Already more than 20 convicted Indonesian terrorists released from prison have rejoined terror cells - some have been re-arrested for new terror crimes.
"The majority of those who have been arrested, and tried, and ended up in the prison system have in fact not yet gone back to their old networks. But the 30 odd per cent that have are the more dangerous ones," Dr Ungerer said.
"Their time spent in prison has not diluted in any way their sense of wanting to be part of a violent extremist group prepared to kill both Indonesians and Westerners."
Dr Ungerer says the prisoners are contributing to a surge in violent jihadi literature in Indonesia.
"Much of this publishing material is actually being done inside the prisons. There are people, convicted terrorists, who are writing, getting messages out from inside the prison system," he said.
"The growth in the number of websites, chat rooms, social media sites that are being used for the recruitment of individuals is growing exponentially. It's targeted at the young, so we're finding that the next generation are now being exposed to all of this material."
Would-be terrorists
Indonesia's counter-terrorism chief, Tito Karnavian, acknowledged the problem last year.
"As long as the radical ideology is growing, extremism is increasing, then we have got really huge reservoir for the would-be terrorist," he said.
The rise of freelance terrorism is in line with Al Qaeda rhetoric, which is also encouraging more individual action.
It now publishes an online English language magazine called 'Inspire', inciting homegrown murderous acts around the world with feature stories like 'Build a bomb in your mother's kitchen to kill the infidel'.
Its publisher is a Yemeni-American named Anwar Al-Awlaki.
"Anwar Al-Awlaki is considered the number one security threat in terms of terrorism today for this very reason - that he is able to reach out in English through this online magazine to youth in countries like Australia, the United States, the UK and Europe," Dr Ungerer said.
"So clearly this is the strategy we see now from Al Qaeda even after bin Laden's death, which I don't think makes a great deal of difference to this particular strategy.
"The strategy is to try and get as many individuals as you can - both in the West and in Muslim countries - to conduct their own operations."
But while freelance terrorism is the latest trend, Dr Ungerer also warns that the re-emergence of a more organised terrorist force could be just around the corner.
Last year the Indonesian police busted a gathering of 300 disparate jihadis at a training camp in Aceh organised by the radical cleric Abu Bakar Bashir. He has since been charged with terrorism related offences.
"What we can expect is that these groups get out of the prisons, they're more hardened, more anti-West, anti-Indonesia, and it won't look like JI anymore, but they'll be new networks and they will be just as dangerous," Dr Ungerer said.
The report by the Australian Strategic Policy Institute will be released on Thursday
( with thanks to the ABC News)