ACLU shredding

Evidently the ACLU is embroiled in a bit of controversy after the head of ACLU’s archives resigned last month in protest over some recent document shredding:

The American Civil Liberties Union has been shredding some documents over the repeated objections of its records manager and in conflict with its longstanding policies on the preservation and disposal of records.

The matter has fueled a dispute at the organization over internal operations, one of several such debates over the last couple of years, and has reignited questions over whether the A.C.L.U.’s own practices are consistent with its public positions.

I can’t think of a good reason why an organization like the ACLU should have anything but total transparency in their records-keeping. Am I missing something?