Some very good and salient points on this thread so far.
I know plenty of ways to get "illicit" goods airside without resorting to holding a family hostage!
I'll outline one, which is obvious enough that it isn't a security risk.
Get your mate who is airside, and has been through security, throw whatever you want over the airfield fence, and then get him to pick it up!
This fight is not one that can be won by frontline security, you can have as many scanners as you like, but you can never defeat it that way. There will always be a weak link in the chain.
The way to fight it best is intelligence driven, with profiling as a back up. I'm sure MI5 and 6 stop an awful lot of stuff before it even comes to fruition. I know where I spend my daily business that MI5 keep a quiet eye on things. That is the way forward.