Bolt_of_Zeus is on point.
I worked in IT for a long time, once video surveillance went IP we were tasked with sourcing and installing such systems. One of our remote facilities would have something like a $100 theft, which was rare, then make requests for budget for a video surveillance system. Since they saw a 10 camera system at Wally World for a few hundred bucks, they came into the request with a VERY unrealistic expectation. They'd want a 50 camera system, and would have just multiplied the cost of a 10 camera system meant for home use by 5. WHOOPS! Those home systems aren't IP, are home grade gear, each run has a limited length, can't be accessed remotely, and just won't do the job.
So I'd go and spend a few hours coming up with a semi accurate proposal of what it'd cost. Going from memory, the numbers were something like this for a 50 camera system:
EACH: Camera: $500 Housing/mount: $200 Cable Drop: $300 So right there we're at $50k for just cameras, housings, and cabling.
All these devices will require available LAN ports on our network switches, and they must provide power over ethernet.
Guesstimate: $10k
Then I can guarantee you'll have to upgrade some of your core switch gear. Guestimate: $10k
NVR server (network video recorder): $10k (50 cams take a lot of space to record, and some decent throughput)
These are thumbnail numbers, but aren't TOO far from reality, and give you an idea how expensive business level gear can be.
So then they'd say "How about wireless!!!". Which we'd have to spend 30 minutes explaining why this was bad, would be overly expensive, cams would still require power (negating the cost savings anyway).
Then as Bolt_of_Zeus explains, somebody would have to go and find video of a person NOT picking up dog poop. So you'd need to need location. If you don't have the time, eyeballing raw video footage, even on fast forward - takes a LONG GOD DAMN TIME. The comes the issue of darkness, and contrary to what you see on CSI, if a camera isn't using an optical zoom lens to get in really close, you can't ENHANCE! the image to get a decent capture if it's too far away.