ScamsEvery country has its scam artists, Indonesia being no exception.
Most are limited and unimaginative but professionals are getting in on the act now so watch out for more sophisticated stuff coming along.Watch out for people hanging around in
shopping centres or supermarkets suddenly stopping you, explaining how they're students collecting for charity.
They commonly want a one off payment.
Their ID cards look very professional, but they're fake.
The people using stands are genuine but one off people hanging around are always scammers.
A polite "No thank you" and look around for a security guard.
If one is there at the time, wave him over and the offenders will be kicked out.
Traffic lights often see 'volunteers' collecting for whatever - many are collecting for themselves.
Again, a polite refusal is best.
Violence from these people is uncommon, so remain polite and avoid confrontation and they'll go away and try to scam the next people.
Those in school uniform are likely the real thing as their principal would kick the lot out of school if they used their uniforms for such a thing. These legitimate collections are conducted in groups, never individuals.
NEVER give money to kids begging - Apart from being illegal (Hardly enforced), many of the kids are not willing, some may even have been kidnapped and forced to work.
Many of the women with babies have hired the kids, and they tend to work in gangsSMS scams have become rare since the introduction of the new security rules. As the thieves must register their SIM cards, they can't send SMS scams without being found out very quickly and arrested
One thing I heard of some years ago.
Woman approaches man.Off to hotel.
Outraged husband knocks on door demanding cash or police.
A cop I know in Java explained that one - seems it's quite common in some areas.
ATM fraudThis happens all over the world, including Indonesia, but it is easily preventable.
Number one trick -
try to use ATMs in supermarkets or other places with lots of security. It's far harder for a skimmer to be installed in places like that.
Many gangs operate in tourist areas, knowing a hit will bag them more cash that locals tend to have, so take special care in such places. The police have a crackdown from time to time but foreign gangs reappear and start again. This is likely to spread to domestic thieves so stick to ATMs in secure areas where possible.
Card copyingThere are two ways they copy your card:
1 - They conduct a transaction in a retail outlet of whatever sort, and run your card through a second reader under the counter. If your card disappears out of your sight, even for a second or two, cancel the transaction, refusing to enter your PIN into their machine as there could well be a camera pointing at it.
2 - Card skimmers on ATMs.
These were easy to spot because they were of lousy construction but the new ones are far more professional.

This short clip is worth a watch.
https://www.youtube.com/watch?v=WYMUA8umUz8Fake websites/CryptocurrencyThese are pretty new in Indonesia but expect more as time goes on. I've just come across a 'koin' site operating from Aceh, they promise the world but the thing is run by a scammer operating out of Panama (or at least that's where the trail leads). The same people having run a lot of fake site scams over the years.
Fake sites are easy to spot if you take a little care and use your head before you get greedy.