You own a restaurant, where you sell poisoned (intentionally and knowingly) food. A group of people band up for class action lawsuit for poisoning them, and have the lawyers post a sign at your restaurant, that everyone poisoned there should reach out and get some compensation.
Should you be allowed to take the sign down?
I know this answer doesn't pass the vibes test, but it's how the law actually works. If you post a sign on someone's property without permission, you'll get in trouble for trespassing, vandalism, or both.
So get a judge to issue an order. In a serious situation, they very well might.
It’s a lawsuit, with the users of the platform as the damaged party, against the platform. Removing the possibility to reach the users should result in a default judgement with maximum damages immediately.