It's in the logs, go see for yourself? GME purchases blocked this morning on apps where Citadel is the clearing house.

SOMEONE proceeds to ladder short sell GME to cause a massive price dump.

Users are margin called from previously profitable positions (without being able to provide buying pressure needed to fight against a ladder short sell)

Shorts are able to unethically cover your position.

Read into this... it's all over the news and verifiable with documentation from various regulatory agencies.