A customer looks over a Glock 29 10mm hand gun at the Guns-R-Us gun shop in Phoenix, Arizona, Dec 20, 2012. With the possibility of new gun legislation on the horizon, many local gun shops saw an increase in sales over the past few days. [Photo/Agencies]

A female polio worker gives polio vaccine drops to a child in Lahore Dec 20, 2012. An alliance of Pakistani clerics will hold demonstrations across the country against the killings of polio eradication campaign workers, leaders said on Thursday, as the death toll from attacks this week rose to nine. [Photo/Agencies]