"At first glance, it may seem odd or even perverse to suggest that statutory controls on the private ownership of firearms are irrelevant to the problem of armed crime, yet that is precisely what the evidence shows. Armed crime and violent crime generally are products of ethnic and social factors unrelated to the availability of a particular type of weapon. The number of firearms required to satisfy the 'crime' market is minute, and these are supplied no matter what controls are instituted. Controls have had serious effects on legitimate users of firearms, but there is no case, either in the history of this country or in the experience of other countries in which controls can be shown to have restricted the flow of weapons to criminals or in any way reduced crime." (Chief Inspector Colin Greenwood, West Yorkshire Constabulary, Police Review, 10 Nov 78, P1668.)
On the author's last trip to England, he found that a legal .45 Colt handgun could be purchased for 500 pounds, and an illegal one for fifty. Purchasing the legal firearm required a police check of the applicant's reputation with his employers, his neighbors, and his relatives; purchasing the illegal one required 50 pounds and fifteen minutes of enquiry of shady characters in a Soho bar. It is evident that their registration system is a failure as a method of firearms control, despite the major control advantages of being situated on an island.
source: http://teapot.usask.ca/cdn-firearms/NFA/firectl.bas
Good point. Of course, most people I know who favor gun controls just fear their neighbors going crazy. Some also fear militias.