Updated

A gun control group on Friday asked two web hosting companies to shut down websites selling devices that are used to make untraceable homemade firearms -- also known as ghost guns.

The Giffords Law Center to Prevent Gun Violence asked that Shopify and DreamHost -- hosts of GhostGunner.net and GhostGuns.com -- disable the websites for violating the hosting companies’ terms of service.

The sites sell kits that help create homemade semi-automatic weapons and can be purchased legally for a few hundred dollars without the kind of background check required for traditional gun purchases.

But Cody Wilson, who runs GhostGunner.net, said the products he sells on his website are legal and in compliance with federal regulations. He said although there is no legal requirement that he conduct background checks, he tries to take precautions to make sure the weapons aren’t used nefariously.

“This is an attempt to apply pressure to deplatform a legal, American business selling legal products to law-abiding customers,” he said.

"This is an attempt to apply pressure to deplatform a legal, American business selling legal products to law-abiding customers."

— Cody Wilson, operator of GhostGunner.net

The Giffords Law Center was founded by former U.S. Rep. Gabby Giffords, an Arizona Democrat who made headlines in January 2011 when she survived an assassination attempt in Tuscon, Ariz.

Attorneys for the gun control group said that homemade weapons are increasingly being used in crimes and asked each of the companies to “invoke its policies to help stem the tide of this illegal, deadly behavior.”

They argue that Shopify and DreamHost should use their ability to terminate the websites, arguing that the two sites sell “the sort of products that have already caused scores of senseless deaths — and are likely to cause many more, unless taken off the market.”

Authorities say that the gunman who killed his wife and four others earlier this month in Northern California built two semi-automatic rifles at his home despite having been barred from owning guns.

Representatives for GhostGuns.com, Shopify and DreamHost did not immediately respond to emails seeking comment.

The Associated Press contributed to this report.