This petition calls for the Obama Administration to introduce legislation that would ban semi-automatic assault rifles and some handguns (e.g., the Glock).
The facts are these: First, while the gun lobby tries to paint a world where the issue of guns is a guaranteed constitutional right, the types of guns available now were unavailable at the time that the Constitution was written. Unlike the muskets used in the late 18th century, weapons today can allow a handful of people to have the same capacity of firepower as an entire regiment in Napoleon's army.
Second, semi-automatic assault rifles and some handguns are not intended for recreational uses, like hunting. Sig Sauers, M4 Carbine assault rifles, and glocks are intended for one purpose: urban warfare, and hence their military use.