The consequences of this have been discussed many times here on PF. Here is an example of what can happen. http://forums.mikeholt.com/showthread.php?t=178779 If you live in a rural community with your own water system or your water supply comes in on plastic this sort of thing seems impossible. But the truth is that you could likely cut the neutral conductor completely off in the service panel and it is unlikely you would notice it if you live in a section of town that everything is well bonded with metal water supply pipe. The current that should be in your own neutral conductor is finding its way back to the transformer through your neighbors neutral. Scary to think that some hack electrician my neighbor may hire could cause problems in my own house. Messing with the neutral can certainly be more dangerous in the long run than being a little careless with one of the hot wires.