From what I understand, not being an expert either but having spent quite a few months in Uganda in the last few years, Museveni has been the president since 1986 and brought a lot of stability to the country, aka brought peace after lots of conflict under Idi Amin. Some people have expressed gratitude for that and fear that Uganda will go back into the violence it faced before and yet seem very tired of the way Museveni has been running the country and want new leadership. Recently, there has been stronger opposition and in the last few years, a popular musician, Bobi Wine, decided to get involved in politics and declared to run for president.

I imagine, if I were in government, I might be afraid of the US, China, Russia, or other countries bringing their political influence into the country through the internet. I might fear revolutions like the ones that happened in Tunisia and Egypt and other countries. I may also just fear my own citizens and what they want. It's hard for us in the US to know how much of the political discourse here is from the citizens vs external sources vs government sources, and I could imagine even harder sometimes in other countries to figure that out.

That's the tricky part with this decision, it could be to stop foreign influences, it could be to stop local influences, it could be to amplify government influences, or a combination of all three.