Start by whipping out clever FOIA requests to find information on it. Dig, dig, then dig more. Find a pro bono lawyer who can do a FOIA suit on your behalf. You'd be surprised by how much information you can get so long as you're patient and can cleverly avoid "unduly burdensome" rejections.

For example, you can now get the Chicago's mayor's phone records by requesting it through their IT department, who asks the phone company to parse their billing logs, which includes the phone records.

Two tabs, and still a work in progress (waiting for their dns resolution logs now for the next step): https://docs.google.com/spreadsheets/d/1hgG79eIr8MbkjYrCvcTR...