Any smoke coming out of electronics is not good for you. The only thing I ever smoked were a SCSI ZIP drive with the power in backwards (yes it fit, flimsy plastic) and a 486 CPU I put in 90 degrees off (never talk with a freind while working), in both cases I smelled something wrong and turned the units off to inspect there was never a smoke clound. Not too bad since I have been working on computers since 1990 or so.
Once you smoke something you need to find out what it was and why it smoked. I would think outside of a power supply frying, a capacitor cooking off, or moisture grounding a 5V line there should not be that much smoke. Don't be too afraid to replace the broken part and still use the machine. I do recommend not running computers in areas without a smoke detector, or leaving them running when nobody is around. Also keep a fire extinguisher around rated for electronics (less of a mess to clean up) just incase something catches on fire (plastic case or whatever).
Generally the PS is fused, and so are most inputs where a user would plug things into (ADB, USB, VGA, etc). I don't think companies bother fusing other areas where they do not expect trouble (like a case screw shorting out a chip).
Once you smoke something you need to find out what it was and why it smoked. I would think outside of a power supply frying, a capacitor cooking off, or moisture grounding a 5V line there should not be that much smoke. Don't be too afraid to replace the broken part and still use the machine. I do recommend not running computers in areas without a smoke detector, or leaving them running when nobody is around. Also keep a fire extinguisher around rated for electronics (less of a mess to clean up) just incase something catches on fire (plastic case or whatever).
Generally the PS is fused, and so are most inputs where a user would plug things into (ADB, USB, VGA, etc). I don't think companies bother fusing other areas where they do not expect trouble (like a case screw shorting out a chip).