Bad actors - whoever they may be - need to see your rights constantly reasserted.
If you want to help pay for lawyers to fight those DMCA notices with counterclaims and lawsuits, put up or shut up; the FSF, EFF and ACLU have been noticeably disinterested in doing so.
It's about arguments in court about the intention of the software if sued. Images of copyrighted content indicate intent to infringe copyright. Without those, you can argue it's only meant to find and index Linux image torrents or whatever.
Fair use doesn't enter the picture at all.
"It then further enriches this metadata by attempting to classify it and associate it with known pieces of content, such as movies and TV shows. It then allows you to search everything it has indexed."