IIRC, violence was hoped to decrease in London when bars were allowed to set their own closing times. Trouble starts when people all spill out of the bars at the same time.
http://www.ctv.ca/servlet/ArticleNew...1123/20051123/
The government hopes the change, which takes effect at midnight Wednesday in England and Wales, will stop the flood of drunks onto city streets just after the traditional 11 p.m. closing time. But opponents say British consumption of alcohol — the most notorious, although hardly the heaviest, in Europe — should not be encouraged.
The new rules allow pubs, bars, shops, restaurants and clubs to apply to open any hours they like, although each license must be approved by local authorities.
Supporters say the changes will end the scramble to guzzle as much booze as possible in the last minutes before closing time and so cut down on alcohol-fueled violence. They hope the new law will nudge Britons toward a Continental culture of gentle tippling rather than relentless chugging.