Non-bank branded ATMs (like the ones you find in gas stations and bars) generally do not have integrated surveillance cameras, so the only surveillance footage would be what is retained by the store's general surveillance system. Stores with digital CCTV will retain 7-60 days of footage, which is enough to aid in almost all credit card fraud investigations.
Bank branded ATMs (especially ones located at actual banks) generally retain at least 90 days of footage, although 365 days of retention is pretty common. Because certain types of fraud can take months to discover, it is worth it for the banks to pay the extra cost to have enough hard drives to store a year's worth of footage. As a federal agent who investigates financial crimes involving banks, I have never seen a bank retain more than two years of general surveillance footage unless they had a reason to suspect a customer or teller of fraud.
90 days on a DVR
After extensive research on this, I'd have to say at least 30-60 days, but especially with the latest DVR systems, some companies may keep up to 2 years of footage easily.
They keep it on 24/7
Forever if they feel that there is something to keep. Otherwise banks keep Video surveillance for 10 years.
one year
no
up to 1month
4-6 hours to go over it but that's a stupid question
That's probably a corporate secret. It can only be answered, if at all, by contacting their Security Department and asking.
Surveillance cameras are legal in just about any public space as long as they aren't hidden.
Certainly, as long as students know they are there.
The formula for calculating square footage is a=S2 (a = area and s = side) Example, to calculate the square footage of a room that is 15 feet wide and 12 long, you would multiply 15 x 12, which will give you the square footage.