[liamdiprose]

If its hosting costs the ACM is worried about, they could offer torrents as a free download option to lighten the load.

[covertlibrarian]

I imagine the vast majority of the digital library is included here:

http://libgen.is/scimag/repository_torrent/

80,700,000 articles as of today. These torrents contain every single article that's ever been accessed through sci-hub. Database dumps at http://gen.lib.rus.ec/dbdumps/ provide an index.