Black Africans in Tripoli
"As rebel leaders pleaded with their fighters to avoid taking revenge against 'brother Libyans,' many rebels were turning their wrath against migrants from sub-Saharan Africa, imprisoning hundreds for the crime of fighting as 'mercenaries' for Col. Muammar el-Qaddafi without any evidence except the color of their skin...
"Many Tripoli residents — including some local rebel leaders — now often use the Arabic word for 'mercenaries' or 'foreign fighters' as a catchall term to refer to any member of the city’s large underclass of African migrant workers. Makeshift rebel jails around the city have been holding African migrants segregated in fetid, sweltering pens for as long as two weeks on charges that their captors often acknowledge to be little more than suspicion. The migrants far outnumber Libyan prisoners, in part because rebels say they have allowed many Libyan Qaddafi supporters to return to their homes if they are willing to surrender their weapons."
From the article as a whole, it sounds like the upper levels of the rebel command structure are trying to get control of this situation, but in the meantime popular prejudice is running rampant. Western journalists found no evidence in Tripoli that the supposed mercenaries ever existed, but I expect a belief that there were to provide support to Libyan racism for years to come. Such prejudice exists already partly due to the idea that migrants are taking jobs from unemployed Libyans.