why not just exclude encrypted zips?

bitmagnet only has the info you get by looking up the infohash in the dht, which is basically the same info that's stored in a .torrent file: a name, a list of files with offsets and paths, and a bunch of block hashes. That's not a lot to go on, and e.g. doesn't tell you if the zip is encrypted

I guess you could filter all torrents that include just zips/rars/7zips. That would exclude a lot of harmless content. Probably too much harmless content to make it a default, but if you only care about hollywood releases it would be a useful filter

If there was a public list of hashes of (8/18KiB blocks of) CSAM content that would be useful for a filter, but I don't think such a thing exists