In the US, it is largely considered that homicide is a *bad thing to do*. As such, if you were to decide that your fellow passenger's music was just too loud to bear and respond by sawing off his head, you would expect... repercussions [*]. A follow-up to such a deed would probably involve a highly extended gaol sentence or, in some states, a ticket off this mortal coil so that your victim can deal with you personally. Largely, similar principals apply in the UK where many individuals enjoys Her Majesty's pleasure at select institutes around the country. In many cases, the long-term punishments dished out in the UK seems to be of shorter duration. For instance, we don't have the death penalty (the ultimate in permanency) and the number of lifers in the UK is 37, where as in the US it's over 30,000 (nope, I did not mis-type that, 37 : 30,000; http://news.bbc.co.uk/1/hi/magazine/7268647.stm). Sometimes, however, the punishment is so severe in the island kingdom that it makes you go cold to think of it... In this particular incident, an elderly gentleman bumped off his wife for refusing to let him go to the pub. Quite a reasonable response in many areas of Scotland. His punishment? House arrest during pub opening hours. Does it really get any more nasty?!

http://news.bbc.co.uk/1/hi/scotland/glasgow_and_west/7540994.stm

[*] This particular crime was actually in Canada, but I find this an incidental detail compared to the actual event: http://news.bbc.co.uk/1/hi/world/americas/7535840.stm