Its all to persuade people that being constantly under surveillance is a good idea and to militarize law enforcement "Oh no another attack/shooting? Let's install more cameras everywhere and arm police with more weapons, that'll keep us safe :D" -__-
Everything has a price, especially in the system most of us live in.
To make you live in fear.
Depends where you live
"security" is a huge business and police want job security-we have thousands and thousands more muders than Canada does while they have 6x the guns we have...and people will swallow the biggest lies if they feel "safe" no matter the loss of rights, etc. -the propaganda is tied in with keeping people out of money and always worried for their safety-just a few reasons from analysis of cause and effect studies on our lifestyles-of course there are other opinions
(RUPERT MURDOCH IS CONTROLLING EVERYONE)
well he owns like a majority of the world's media