And the answer from it's cofounder

"My miningpool-observer project recently reported six OFAC-sanctioned transactions as missing from blocks.
Four of these transactions were likely filtered by F2Pool. This is the first filtering based on OFAC sanctions I've seen."
https://b10c.me/observations/08-missing-sanctioned-transactions/
And the answer from it's cofounder

Looks like he’s deleted the post and is hiding replies on his recent thread.
Excellent understanding of what #Bitcoin stands for. Moar of such marketing pls
Already deleted these tweets, pussy 😂
How to destroy your pool 101
Currently it doesn’t look like that miners switching to a different pool F2 has found blocks on the same rate like normal.
Strange 🤔
He's right. He has the right to do whatever he wants with his pool. Hashes can leave whenever they want.
That’s how it works
Capitalism solves this