In case you were wondering, the U.S. Department of Homeland Security does have an office dedicated to civil liberties issues: the Office for Civil Rights and Civil Liberties (OCRCL).
"The Office was created by Congress to review and assess allegations of abuse of civil rights or civil liberties, racial or ethnic profiling, by Department of Homeland Security Personnel. The Office is required to report annually to Congress on any such abuses committed by DHS personnel, how much money was required to resolve such complaints, and how such complaints were resolved."
Note that the office is answerable not to people whose liberties may have been infringed, but to the congressional budget.
Read that however you like. The size of this DHS branch is not specified — it may be as few as a half-dozen people. The current OCRCL hot-button (if you can call it that) appears to be not First Amendment issues but racial profiling (an admittedly heinous practice), but bureaucratic delays may also function as a rear-guard action.