Why are there so many armed groups in eastern DRC?

Africa Daily - A podcast by BBC World Service

On Wednesday a small group of people attempted to protest on the streets of Goma in eastern Democratic Republic of Congo. They said they were dissatisfied with the East African regional force which has been deployed in an attempted to restore peace in the region. The border region in the east of the country has seen decades of violent conflict. In recent years, larger rebel groups such as M23 and the Allied Democratic Forces have made headlines. But there are hundreds of smaller groups contributing to the instability there. So, who are they?#AfricaDaily