[JupiterMoon]

How long ago was this? The quality of the images from CCTV has increased a lot in recent years. See for example the number of people convicted after the London riots. And combined with gait analysis (did you know that most people's walk is fairly unique) and tracking of their cellphones its even more effective.

[Cthulhu_]

That's what I've always wondered really, why are CCTV's often so bad? The old systems (from what I've seen on TV anyway) seemed to put the image of four cameras onto one video tape, reducing quality even more.

Of course, a million cameras running 24/7 produce an enormous amount of data, that just increases exponentially as quality improves. They can probably easily discard 90% of the footage with basic checks (is there anything besides the background visible), and use a smart compression algorithm, but still.

[JupiterMoon]

Even for home systems it is possible to set up a system that only records when there is movement present.

[gaius]

3-4 years maybe

[JupiterMoon]

How old were the cameras?

[gaius]

No idea. The ones outside tho' I'd guess were normal, unless they upgrade every one of those million cameras every few years.