Quick summary for those of you not watching the video:
* Contraband has been revamped! Lots of new sources for contraband (almost every room has something to offer), lots of new types of contraband.
* Contraband tracking! Contraband located by guards will be shown on the map, along with a 'trail' on the map showing where the contraband was obtained, how the prisoner moved it, etc.
* Shakedowns and searches! Order guards to search a prisoner and his cell (every constructed object can be used to hide contraband), or stage a shakedown of the entire prison. Be warned, though - prisoners don't like being searched unnecessarily!
So far, it looks very interesting. This also looks like a first step towards making 'Free Time' less overpowered - too much free time means lots of chances for prisoners to smuggle drugs through the visitation room, or slip into the workshop to snag weapons and tools.
The game still needs some way to circumvent metal detectors, though. Prisoners will now attempt to route around metal detectors when picking up metallic contraband, and are less likely to steal something if there's no safe route. The problem with this is obvious - if you put a metal detector across every exit from the workshop, you've just stopped any workshop contraband from getting out! Maybe make metal detectors 'bottleneck' prisoners, slowing them down if they're moving through in large numbers? Or let prisoners squeeze past metal detectors if there isn't a guard watching?