When I first started to work for the State of Michigan, I was told that the legislature had their own telephone system. This was partly because of wire tap concerns and partly because FOIA requests. They were afraid that requests for telephone records under FOIA would be given out without their consent. In short, they didn’t have to comply with FIOA requests if they chose not to.
However, in the light of recent media events, they are looking to change their FOIA exemption. But given the general paranoia that the legislature seems to have, I doubt that anything will change regarding FIOA requests.