well, some of them might possibly be under ceratin circumstances, hence why MS is replacing power cords for XBoxes manufactured before Oct. 2003. for more info go here: http://www.firingsquad.com/news/newsarticle.asp?searchid=7712
to get a new cord go here (US only for this link):
http://replacements.webprogram.com/dakota/en-us/index.asp
to get a new cord go here (US only for this link):
http://replacements.webprogram.com/dakota/en-us/index.asp