Actually hor, it's quite safe if you know what you are
doing.
One of first rule of self-defence is to always avoid danger and
conflict if you can, unfortunately I think could it be that
Singaporeans simply lack the street smarts to keep safe in JB
that's why they end up such easy prey?
Always keep to crowded, well lit areas. Never enter a place where
you are not certain of how to escape. Don't walk blindly around
without noticing who might be targeting you and don't look like the
ignorant Singaporean moving around in JB but just blend in to be
like one of the locals. Always make sure you have a plan on what to
do if you encounter criminals and if you can travel in groups. And
don't silly silly follow strangers after they tell you some funny
story. And don't dress so nicely if you can, something simple will
do.
It is likely the cases of Singaporeans who were robbed in JB, very
often they failed at one of these crucial things and ended up being
a nice target. Remember this is not Singapore so don't treat it
like it's Singapore and you will be safe just by acting as you
always do in Singapore.
