SEFA Riano didn't try to hide his plans or his beliefs.
A Facebook page police traced to him is plastered with photos of bearded men in camouflage uniforms holding rifles and banners hailing "The Spirit of Jihad."
One status update in late April apologises to his parents before telling them goodbye.
Another declares ominously, "God willing, I will take action at the Myanmar Embassy, hope you will share responsibility for my struggle."
It ends with a yellow smiley face.
Days later, police arrested Riano, whose Facebook name is Mambo Wahab, just before midnight in central Jakarta.
Police say he and another man were on a motorbike carrying a backpack filled with five low-explosive pipe bombs tied together.
Riano, 29, is awaiting charges related to allegations that he plotted to bomb the embassy to protest the persecution of Muslims in Buddhist-majority Myanmar.
A police investigator revealed Riano's connection to the page, which was still online Thursday, to The Associated Press.
The investigator spoke on condition of anonymity because he is not authorised to talk to reporters.
The investigator said Riano caused his own downfall by publicising his mission on Facebook, but added that police believe it was another Facebook page that drew him to radical Islam to begin with.
Police said a growing number of young people in Indonesia, the world's most populous Muslim nation, are being targeted for recruitment by terrorists on the social media site.
More than one in four of the country's 240 million people are on Facebook, thanks in large part to cheap and fast internet-capable phones.
While it is not clear how many terrorists are actually recruited through Facebook, the use of social networking to groom potential attackers poses new challenges for authorities struggling to eradicate militant groups that have been weakened over the last 10 years.
Though Facebook shuts down pages that promote terrorism when it learns of them, police say new pages are easily created and some have attracted thousands of followers.
Muhammad Taufiqurrohman, an analyst from the Centre for Radicalism and De-radicalisation Studies who works closely with Indonesian anti-terrorism officials, said 50 to 100 militants in the country have been recruited directly through Facebook over the past two years.
He said there were at least 18 radical Facebook groups in Indonesia, and one of them has 7000 members.
Police said some sites where radical discussion takes place focus on Islam, while others engage in talk about committing violence, such as how to make bombs.
Access is blocked unless group administrators allow users to participate.
Indonesian police say Facebook is one of many places where they've found terrorist activity online. They have detected militants using online games for attack drills.
A group was caught uploading propaganda videos on YouTube and terrorists are known to have purchased weapons using video calls, said Brigadier General Petrus Reinhard Golose, the director of operations at Indonesia's anti-terrorism agency.
Terrorists have used the internet for many years, but usually anonymously.
Groups such as al-Qaida have employed online discussion forums where people left comments but did not directly interact.
Today's smartphone generation appears to be operating more openly: As of Thursday, Riano still had about 900 Facebook friends.
The police investigator said authorities were alerted about "Mambo Wahab's" Myanmar bombing status update by other internet users.
Police used information collected from arrested militants in Riano's online networks to track his Web footprint.
After getting his internet protocol address and eventually linking that to a mobile phone, authorities say they were able to tap into conversations involving Riano and the plot's alleged mastermind, the investigator said.
The Mambo Wahab page has not been updated since Riano's arrest May 3.
Some people in Indonesian jails - even on death row - manage to post status updates, though others may be acting on their behalf.
Some Indonesian police want the law to address online communications that advocate or abet terrorism. Indonesia's information technology laws ban only pornography and illegal online financial transactions.
The government is drafting legislation that would criminalise hate speech and online terrorism activities.
Although police are starting to surf the internet as part of their work, many of those arrested for terrorism-linked activities on Facebook were caught not because of cyber patrolling, but because police received tips about their accounts.
Those cases include nine militants, including one woman, who were sentenced to up to 10 years in jail for funding terrorism activities by hacking into a Malaysian website and defrauding the company out $US800,000 ($A866,500) in cash and assets.
Indonesia has fought terrorism aggressively since the 2002 Bali bombings, which killed 202 people, mostly foreign tourists.
There have been no large-scale attacks for several years, though there have been several smaller strikes targeting mainly the government, police and anti-terrorism forces.
Well-funded terror networks have been disrupted, but radical clerics continue to spread their ideology to militants who set up military-style training camps.
