it depends why it's being used.
saturday night - town centre - in theory at least it contributes to a safer place
as with any system it's a contributor ... people monitoring react to what they see - it's possibly a deterrent - but there will always be a delay between action and reaction ...
if it's used responsibly "ordinary" people should have nothing to fear
but it's always open to abuse ...
Tesco etc monitor our buying habits via loyalty cards
credit card providers will contact you if your card is being used in an unusual way
ISPs monitor our surfing habits
BT has been accused (along with many other ISPs of selling this info to a targeting advertising company)
pedophiles are caught because chatrooms etc are monitored.
and sony have just prosecuted 100s for downloading pirated media
personally I'm not particularly bothered - I'm not that exciting or outstanding that anyone would be interested in anything but my ridiculously wasteful buying habits.