specifically https://annas-archive.se/torrents - this is a meta-project which aggregates illegal copyrighted material from other illegal projects. You absolutely should not download any material this page links to, although you can use it for the purpose of researching about shadow libraries.
Weird shenanigans are happening in libgen at the moment; better go through Anna's Archive to look for the items you want, it will link you to the corresponding mirrors more reliably.
At least this has been the recent experience of a friend who used libgen and anna's archive to download legal, public domain works!
