There are in home and on the street security problems.
I will focus first on home security and home invasion problems.
These are some observations suggestions from what I have seen and has happened in my neighborhood, 7 home robberies in the last three years in my immediate area.. I am focusing on the expat style homes. Maids are also part of the crime scene as they can call their friends to come when the expat leaves for a while. Their friends either enter the house or products are thrown over the wall/fence to their friends. Boys hanging on the street in groups also watch who come and mostly go in their cars and they know the house is unattended. So be alert, always.
The best prevention to start off with is to have a night Security Guard. However even the security guards have been compromised in many home invasion robberies and found to work with the criminals. In my opinion the Security Guard is not much of a deterrent except as a witness to problem or in between hour long naps at night can deter the borderline individual and the "honest" criminal from entering the property.
Locks on doors and widows that are secure by key or double bolt is weak security (like a four digit code1.2.3.4). You need a crossbar across the widows and doors and hand locks up and down the widows and doors- all old style but very secure.
Good to have bright lights all around your property at night and security cameras.
Good guard dogs can be a first alert if you are sleeping.
Cement walls with barb wire on top of glass shards and widows covered with rebar.
All of which becomes close to useless for the crooks wait for rains and the noise of the rains that block out the intruders actions and thus electric is turned off by jiro or the crooks and dogs are feed beef laced with poison, barb wire clipped and blanket thrown on top and rebar quickly cut for access to the interior of the house.
Expats owning guns is an issue and has been mentioned that the shotgun can be legal for hunting so that means hand guns are illegal though I was introduced to an arms merchant that wanted to sell me a pistol for $900 dollars without any bullets. The pistol was crap and looked handmade and thought it might explode in my hand.
Best you build your own one shot slam gun for $30 but you need to find the bullets first,- Slam gun instructions can be found on you tube and built in 4 hours.
Build a extra security door to your sleeping quarters. The noise of them trying to break in will put you in the fight position rather than woken up with a knife or gun to your head.
Water guns can be filled with toxic sprays from acids to red chili seeds boiled in water and filtered down to pure spicy hot water to provide a spray similar to mace and directed to their eyes, and even wasp spray found in the market can shoot about 10 feet to slow down the criminal.
spears can be made from grinded down rebar to a point and knifes and machetes are a given.
A practiced escape route for the family perhaps on the roof, is also important especially when the attack is by 7 or more men/boys.
If you hear a weird noises and activities outside your door---Do Not Open Your Door and Think you will go outside- you will be overpowered.
Have several whistles or a noise machine and alert the neighborhood, keep the police number on your phone, call and hope this is the evening they are in the mood to take action and be prepared to pay for what they say is their gasoline.
What else?