It's interesting that intelligence agency oversight was almost exclusively an Executive Branch function until the mid-70s. The formation of the Church Committee in the Senate and the Pike Committee in the House were prompted by media reports to look into CIA operations. As a result, the House and Senate each created their own select committees on intelligence. Now the House is considering a change to its rules to provide for the inclusion of some House intelligence committee members on the House Appropriations Committee in order to exert more control over CIA activities. However, it's not clear if such control would also extend to the DIA and other federal intelligence agencies. There are a ton of them and one would think that they could combine their operations. But turf is important in any organization and the feds are no different.