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No. You own your data stored at Facebook. Facebook just have license to use "as they wish" while respecting your privacy settings (i.e. uploading facebook.tax.xz is definitely not according to privacy settings of most people).

At least that written and TOS or so.

If they did that with any European data, they would soon face criminal charges.

(Except if a European office of Facebook did it, then the nationality doesn't matter.)

I wonder if archive.org could actually store that much data.. and how long it would take to create a tar.xz of it.

What file systems would support a tar that big?

https://en.wikipedia.org/wiki/ZFS