Preman is people who lives or resides in certain place or area, and is widely known by locals who also lived there because of her/his intense existence around that area. In my opinion, his/her intense existence occurs because maybe they are unemployed, that is why some people said word "PREMAN" comes from english phrase "FREE MAN". They have nothing to do, hence the word free. Some preman also known because they're claimed to be the "owner" of certain place or area, and that's why comes another phrase "PAJAK PREMAN" where someone should pay when they walk pass/within Preman's area. Now and then, Preman linked to street crimes and vandalism, street gamblings, alcohol, people with tatoos, etc.

A preman is a member of an Indonesian organized gang, encompassing street level criminals up through crime bosses. http://en.wikipedia.org/wiki/Preman_%28Indonesian_gangsters%29

thugs in Indonesia often mean people who commit crimes, but it is actually not a thug status. This can be done by people who are educated or even could have been by the state

The word is a combination of the words "free" and "man". A person who looking for freedom

preman could mean gangster or criminals on the street, bad people that wander around in some places.