Sometimes when a computer "dies" it's only one component that's problematic (for example the video card). They replace the faulty parts, etc. so they work again.
It really depends on where you're getting it from, the specific specs of the machine, and how much it costs to buy a similar one new. Sometimes they ARE worth it, sometimes they're not. Unless you know what you're doing, I wouldn't really recommend buying refurbished except from a reputable company (ie. directly from Dell or whatever other original manufacturer).
And um... I'm not sure the easiest way to explain this, but the whole "used it and they have the ip number" is just WAY wrong for several different reasons.
As far as security, again, if you don't really know what you're doing, only buy from reputable sources.
at 3:32 PM on Aug. 13, 2010