I wonder if they're taking precautions against the blimps being shot down.
Contrary to (popular?) opinion most of Africa is not a warzone. With extremely few exceptions (Somalia, and the Democratic Republic of Congo), most of Sub-Saharan Africa is in the middle of an extended period of peace. It's inconceivable that if ever deployed, any of these blimps will be interfered with in the airspaces of East Africa (aside from Somalia) or over any country south of them.
[1] http://www.suasnews.com/2012/11/19719/activists-drone-shot-o... (Yes, the drone may have been above private grounds; so probably will the blimps)