FediBlock is a volunteer group which recommends Fediverse instances to block due to hate speech etc. You can follow them at:
➡️ @fediblock
Their website is at https://rathersafe.space/fediblock
As a safeguard against malicious blocking, blocks are voted on by the volunteers, with single votes against enough to stop block recommendations.
❗ IMPORTANT NOTE: Despite the similar names and similar logos, I have no connection to FediBlock.