https://annas-archive.org/volunteering
Be aware that helping Anna’s Archive may be illegal, or even criminal.
A different, more legal archiving effort is the Archive Team. It focuses on public data on the internet. https://wiki.archiveteam.org/index.php/ArchiveTeam_Warrior
In some places without a strong freedom of information tradition (like the EU), this may still be illegal.
Hmm. Per Facebook v. Power Ventures, it could be a (criminal) violation of the CFAA to “circumvent” IP blocks.