It appears that the Central Bank of Kenya considers bitcoin, and cryptocurrencies in general, to be a threat, and has issued a statement discouraging the use of bitcoin in Kenya.
Their justification for this stance is their assumption that the unregulated nature of the Bitcoin protocol encourages its use for terrorism and money laundering, even going so far as to place the notice in newspaper ads.
Here’s the public notice [PDF].
As the Bitcoin protocol allows for peer to peer transactions between people, without the need of an intermediary who adds no value to the transaction, the only jurisdiction the CBK can truly exercise is over Kenya’s national currency, the Kenyan Shilling (KES). As any exchange agent that provides the services of exchanging fiat national currencies to/from bitcoin, they have to take into consideration and contend with the laws governing the fiat currencies that they are transacting with.
It seems that the CBK has a limited understanding of the full range of features available within the blockchain, which include the advantages of faster transaction times, independent verification of payments without