Conflict minerals (like gold and tantalum) are present in most of our commonly used electronics. These minerals are generally attained through intense social exploitation (i.e. child labor) in disastrous mines that cause extreme environmental degradation for their surrounding areas. Countries like the Congo that are rich in natural resources but are politically unstable are ravaged by war and violence because of this mineral trade that is fueled by western consumer demand for electronics.
Next time you consider purchasing a new phone or laptop, consider first if you really need a new one. If you determine that what you have isn't sufficient, consider buying a refurbished one instead You can also refer to the Enough Project's company rankings, a rating system that evaluates corporations on their efforts to be "Conflict Free."
There is currently an initiative at UC Santa Cruz to become a conflict-free campus. For more information about this effort, please contact Leeza Arbatman, President of STAND, a student anti-genocide coalition that is currently focusing on these issues. Email her at earbatma [at] ucsc [dot] edu.
Read more about the ways that conflict minerals affect people living in the Congo in this National Geographic piece.