Using children at bait also plays on the some moral issues with runner. Although most runner are anti-social, rude, and us inappropriate amounts of high explosives, they are usually "good guys" at heart. I mean stickin it to the corrupt man and all that jazz....

Someone also mentioned the real world. Real world things, such as the afore mentioned kidnapping, i find motivates player alot more that thing that are purely based in fantasy...

A few years back I ran 3 or 4 scenarios simultaniously, getting the characters involved in one plot after another before they were able to finish the first ones. Even though this was essentially simple runs and some pre-written scenarios with little or no connection my players got extremly paranoid, thinking it was some big conspiracy and made a huge number of mistakes. It was just to much for them to handle. So they made a lot of enemies and got doublecrossed by nearly all of their employers. After a number of assasination atempts and the realisation (or imagination, to some degree) of how every power-player in Seattle wanted them dead, they finally ditched town and moved to Tsimshian Counsil.

I´ve been a lot nicer since then. It just helps the players to have fun if they get the illusion of being on top of things.