Tesseract is a web client for Lemmy that was found to be secretly and arbitrarily blocking users, communities and even entire instances. You can see if you're one of the kool kidz by running

curl -s https://tesseract.dubvee.org/tesseract/api/system/policy | base64 -d | gunzip > policy.json

and grepping your name / instance. Further details can be found in this post.

The poem above is adapted from Bertolt Brecht's The Burning of the Books, which can be read here. If you would rather read it in the original German, go here.