A girl holds a slate with alphabets and numbers along a path in the Koluama village in Nigeria's Bayelsa state May 15, 2012. Nigeria is Africa's largest crude oil exporter but its production capacity has been slashed by thieves drilling into pipelines passing through winding creeks and waterways in the vast delta. The underground industry is thought to be worth hundreds of millions of dollars a year.Those who engage in this underground business claimed marginalization from basic education, access to good health facility and employment from the national oil revenue.

Labourers paddle a canoe containing drums used in siphoning crude oil for an illegal refinery, seen in the background with smoke, along the Diebu creek in Nigeria's Bayelsa state, May 15, 2012. Nigeria is Africa's largest crude oil exporter but its production capacity has been slashed by thieves drilling into pipelines passing through winding creeks and waterways in the vast delta. The underground industry is thought to be worth hundreds of millions of dollars a year.Those who engage in this underground business claimed marginaliszation from basic education, access to good health facility and employment, from the national oil revenue.

A man carries a bucket of crude oil at an illegal oil refinery in the village of Isuini-biri along the Diebu creek in Nigeria's Bayelsa state, May 15, 2012. Nigeria is Africa's largest crude oil exporter but its production capacity has been slashed by thieves drilling into pipelines passing through winding creeks and waterways in the vast delta. The underground industry is thought to be worth hundreds of millions of dollars a year.Those who engage in this underground business claimed marginaliszation from basic education, access to good health facility and employment, from the national oil revenue.

Smoke rises from an illegal oil refinery along the Diebu creek in Nigeria's Bayelsa state May 15, 2012. Nigeria is Africa's largest crude oil exporter but its production capacity has been slashed by thieves drilling into pipelines passing through winding creeks and waterways in the vast delta. The underground industry is thought to be worth hundreds of millions of dollars a year.Those who engage in this underground business claimed marginaliszation from basic education, access to good health facility and employment, from the national oil revenue.

A signboard campaigning against oil pipeline vandalism is seen along a road in Yenagoa in Nigeria's Bayelsa state May 15, 2012. Nigeria is Africa's largest crude oil exporter but its production capacity has been slashed by thieves drilling into pipelines passing through winding creeks and waterways in the vast delta. The underground industry is thought to be worth hundreds of millions of dollars a year.Those who engage in this underground business claimed marginaliszation from basic education, access to good health facility and employment, from the national oil revenue.

Thatch houses line the Diebu creek in Nigeria's Bayelsa state May 15, 2012. Nigeria is Africa's largest crude oil exporter but its production capacity has been slashed by thieves drilling into pipelines passing through winding creeks and waterways in the vast delta. The underground industry is thought to be worth hundreds of millions of dollars a year.Those who engage in this underground business claimed marginaliszation from basic education, access to good health facility and employment, from the national oil revenue.

Labourers walk on a canoe used in siphoning crude oil for illegal refinery, after stealing the oil by tapping on a flow station, along the Diebu creek in Nigeria's Bayelsa state May 15, 2012. Nigeria is Africa's largest crude oil exporter but its production capacity has been slashed by thieves drilling into pipelines passing through winding creeks and waterways in the vast delta. The underground industry is thought to be worth hundreds of millions of dollars a year.Those who engage in this underground business claimed marginaliszation from basic education, access to good health facility and employment, from the national oil revenue.

An oil slick flows at the base of a mangrove near an illegal oil refinery along the Diebu creek in Nigeria's Bayelsa state in Nigeria's Bayelsa state May 15, 2012. Nigeria is Africa's largest crude oil exporter but its production capacity has been slashed by thieves drilling into pipelines passing through winding creeks and waterways in the vast delta. The underground industry is thought to be worth hundreds of millions of dollars a year.Those who engage in this underground business claimed marginaliszation from basic education, access to good health facility and employment, from the national oil revenue

A plastic container, which contains crude oil siphoned for an illegal refinery from a flow station, is seen on a canoe along the Diebu creek in Nigeria's Bayelsa state May 15, 2012. Nigeria is Africa's largest crude oil exporter but its production capacity has been slashed by thieves drilling into pipelines passing through winding creeks and waterways in the vast delta. The underground industry is thought to be worth hundreds of millions of dollars a year.Those who engage in this underground business claimed marginaliszation from basic education, access to good health facility and employment, from the national oil revenue