On Thursday at 9:30 am Eastern time, US attorney general William Barr will hold a press conference to discuss the release of the Mueller report. The only problem? No one outside of the Justice Department will have seen it yet. Instead, according to reports Wednesday night, the DOJ will deliver the report in full to Congress sometime between 11 am and noon. On compact discs.

Pundits have slammed Barr’s rollout strategy, particularly the delayed release of the report itself. But the use of CDs—a medium that rose to dominance when Barr first led the DOJ but has fallen precipitously since—has also raised eyebrows. In the year of our lord 2019, why use a hard copy at all? Why not simply email the file as an attachment, or host it on a site or server somewhere? Surely that would be more convenient.

Despite the jokes about Columbia House and AOL, businesses built on the humble CD, sending the report to Congress on compact discs isn’t as strange as it might seem.

First, there’s the capacity. A typical CD can fit 700 megabytes of data. For perspective, that’s about the size of a tightly edited Game of Thrones episode in standard definition. (Going full 1080p bumps you up to 2GB and beyond.) The nearly 400-page Mueller report—exclusive of tables and appendices—likely won’t come anywhere near that. Assume Barr distributes the report as a PDF, and another point of comparison becomes useful: The heavily redacted FISA application for surveillance of former Trump campaign adviser Carter Page weighs in at a healthy 412 pages. It’s 7.8MB; were you to put it on a CD, you’d have a healthy 692MB left over, give or take. That’s a lot of tables and appendices.

What if it’s not a PDF? Not much help there, either. The 1,000-plus pages of Leo Tolstoy's War and Peace rendered in HTML takes up 3.9MB. In a Kindle-friendly format, it’s 5.4MB.

It’s unclear what sort of email size limits Congress has to deal with, but an internal IRS document suggests capping attachments at 10MB. A former congressional staffer tells WIRED that it maxes out at 20MB. The 448-page Mueller report PDF landed at 145.5MB, making email clearly unviable.

Regardless, this point turns out to be moot. “I have no idea what the max size is, but that is obviously not the reason they are bringing hard copies,” says one Senate spokesperson.

The answer is likely much more straightforward. One former White House staffer tells WIRED that distributing sensitive material—even if it’s not classified—as a hard copy was not uncommon. It helps minimize the chances that those documents will go more places, faster, than intended. Barr critics might here see another attempt to control the narrative; it will take Capitol Hill staffers longer to dust off their CD-ROM drives than it would to double-click a file. And given that the Mueller report is supposed to be posted publicly soon after, it’s not immediately clear why he would feel the need to control dissemination.

It’s not quite that simple, though. Certain members of Congress will receive a version of the Mueller report that has fewer redactions than the one the public will see. Specifically, their copies will have much more information about Roger Stone, whose sections will be more heavily obscured for the broader audience because he’s the subject of an ongoing criminal investigation. It makes sense to try to limit the leaks on that however possible.

But still, a CD? There are other ways to share hard copies of large file these days. Still, many lawyers didn’t bat an eye at the revelation, given that CDs remain a popular way to share electronic stored information in the discovery phase of a trial. In fact, it’s recommended. “Generally, the producing party will provide disclosure of responsive data to the requesting party’s ESI production request by physically transferring the data by CD-ROM, DVD, hard drive, or other storage media,” reads the 2018 edition of Arkfeld's Best Practices Guide for ESI Pretrial Discovery - Strategy and Tactics.