I often watch a TV commercial from a well known alarm monitoring company in which the alarm goes off after an intruder breaks the door down.
It always makes me chuckle as the operator says "I am sending help right now", which would you rather have ;
1) help being sent now (arrival indeterminate maybe 5 min)
2) Loaded shotgun in hand now ?
Also note the intruder always leaves after the alarm goes off, what about the 5% of the time when he doesn't ?
Having worked in my youth as a locksmiths apprentice, I can tell you any kind of lock or even barricade is just a deterrent.
If someone really wants in, they will get in.
It is prudent to make a premise as secure as possible, and to have an alarm with monitoring, but when all else fails, the means to defend oneself and loved ones is essential!
Most of the US except the Northeast ( New York for example only permits cops and criminals to own guns) allow lethal force when an intruder enters;the south and west (except for Peoples republic of Kalifornia) do all cases.

Hopefully the Supreme Court will uphold the 2nd A for all of the U.S.

Canada seems to be coming to it's senses at least with respect to registration, this should be a lesson for the U.S. as well, if it didn't work in Canada it certainly will not here.

In the mean time, a defense in depth consisting of as many layers as possible is best, alarms,lights (motion sensor type), good locks,kick-plates,latch plate reinforcements,pepper spray and last but not least a firearm.