It's so that they can nail you to the wall with the evidence you willfully sent them when they take you to court.

Damn straight. Do not engage these people, do not answer any correspondence - speak to a lawyer if they proceed to legal threats.

This. They're just gathering more evidence by getting you to hand them a hard drive with this on it.

Good point, getting legal advice before doing anything seems like a safe plan!

Yeah, I'd definitely send some unused external hard drive only containing the "stolen" data. And I also find this overkill and ridiculous, I wouldn't think anybody would ever do that in 2014. But then you have majors suing people who uploaded 1 song for million bucks, so, don't be a hero and call your lawyer!

Be sure to enable full-drive encryption first. They just asked for a hard drive they could copy and erase; they didn't say jack about it being in a readable format.

See also: formatted with DragonFlyBSD's "Hammer" filesystem. Archived in BinHex. Saved with Base37 encoding. And 9-bit bytes. In the "/home/leopard/music" directory of a fresh Debian Potato install.

The letter just asks for a copy of all the data downloaded on a hard drive, meaning they just want to see what you have copied and named a hard drive as a particular medium to receive the data on.

It's clear that they intend for it to be an otherwise clean drive, since the mention they're going to wipe the drive before returning it.

Again, they're not asking for any specific drive, just that you turn over a copy of all the data collected on a medium that's easy for them to use.

Maybe they want to check what data was scraped?

My thoughts exactly.