My own house also has blade-topped fences, I have an electronic gate which requires a 6-pin entry pad and a thumbprint. I have 3 dogs, double-plated steel doors and retractable window bars.
Some fucker broke in through the ceiling last week while I was asleep and stole my iPhone and wallet.
The reason we do this in South Africa is because of safety. Home invasions, car jacking, mugging, kidnapping are everyday occurrences here. I know of 3 people who have been killed during one of these engagements and everyone I know knows someone who has died.
If you worry about your kids wandering the streets in America, Canada, New Zealand.. Come to Africa and get some context.
Possessions are meaningless, your health and your friends are what counts. That's something some people learn the hard way in this country.