Check in security/deposits

I was wondering what sort of security and deposit system people are using.

I've been in hostels where they ask for nothing, just money up front and give you the key. I've been in other places where they want deposits and forms to fill with all sorts of questions.

I guess it depends on region to region and country to country, but I'm just wondering what the checkin/security is for anyone who runs a place. I was thinking perhaps payment up front, plus a deposit, refundable after. I also thought perhaps a form with rules and regulations to sign, then maybe scan a copy of their passport to my computer.
That way if there is any damage and they try and skip out I can pass their details on to the authorities - I mean you never know what people could do.
I would also have the whole place covered by CCTV; outside the front door, directly behind the desk, along the corridors and in the common room. (but not the rooms or bathrooms obviously)

I'm sure some ppl might think that somewhat excessive, but in my experience, when it comes to people, it's always best to be prepare for the worst, that way it's always a joy when you see the best. Strong security also acts as a deterrant, ppl are less likely to mess around when they know you're watching them and can catch up with them.

It's a conflict of interest really, deep down I'm an advocate of privacy and I'm repulsed by the "camera culture" we've become yet @ the same time I know that this is the age of ignorance and as long as society as a whole continues to eschew personal responsibility, the self-employed people need the invest in all this draconican crap.

Oh well, what kind of security and deposit systems do you all use or have you come across - what's the most common, and, in your opinion, what's the safest and most practical.