I think Barry's right that taking contacts etc home can be construed as theft. Think of it this way: If a company wants me to work from home and they provide me with a laptop to do so then that would be fine. If I take it upon myself to work from home and take a laptop without telling them... not so fine. Contact lists, code etc are exactly the same. It's the companies property and if they're happy for you to take them home then great, but if you do so without their consent you're into very dodgy ground.

As for getting people to work their notice period or not I don't think you can set a hard and fast rule. I think it depends on the individual and the circumstances they're leaving under. If they've always shown integrity and have handed in their notice because they've got a new opportunity, for example, then I'd want them to work the period. If they've always been a bit dodgesome and the company has felt the need to fire them then obviously get rid ASAP. Everything in the middle is a grey area and is, at best, a judgement call.