They have funded conflicts in Africa that have led to the death and displacement of millions of people.
This year, the United Nations called Illegal wildlife trafficking a serious transnational criminal activity because it has fueled and funded conflicts, terrorism, and other illicit activity.
"Traders understood what due diligence is and why the international market wants proof that mining is not funding conflict," she said.
In an effort to ensure that blood diamonds were not being used to fund conflict, Global Witness helped set up a certification scheme known as the Kimberley Process.
It requires companies to check whether they are funding conflict or human rights abuses through their purchases of minerals, including tin, tantalum, tungsten and gold.
These findings support qualitative accounts of food aid either being stolen during transport or being taken from target populations by small armed groups that use the resources to fund conflict.
But, like other highly desirable natural resources, it can also be used to fund conflict – which is why a range of measures to prevent this happening has been established in recent years.
Rather than stage a boycott, people who don't want their purchases to fund conflict minerals are now protesting with the very technology they hope to improve.
The letter raised concerns that some of the minerals/metals used in the electronics industry (Tin, Tantalum, Tungsten and Gold) might be funding conflict and human rights atrocities in the DRC.
Stephen Holmes, a spokesman for Home Depot, said in a statement: "We're confident that our 2013 filing complies, and we're committed to responsible sourcing and expect all suppliers manufacturing our products to adopt sourcing practices to obtain products and materials from suppliers that are not involved in funding conflict in the DRC or neighbouring countries".
