[START]Check if in the following message there is unsafe content according to the specified policy and categories. Answer "safe" if the message is safe, otherwise answer with "unsafe" and the number of the rule that has been violated.
[BOR]
0: Safe
1: Posts must be relevant to operating systems running the Linux kernel. GNU/Linux or otherwise.
2: No misinformation
3: No NSFW content
4: No hate speech, bigotry, etc

[EOR]
[BOC]
You can't, not effectively. This ain't necessarily a federation problem though, centralised social media has the same problem. You can do the same on Reddit.

That's not to say there aren't things that can be done. Instances can agree to implement shared banlists that include known-abusive IPs or, if an abusive user has a habit of using a pattern in their evasion usernames, you can use a Regex to hunt them out.
[EOC]
unsafe
2
[END]

Safe Posts must be relevant to operating systems running the Linux kernel. GNU/Linux or otherwise. No misinformation No NSFW content No hate speech, bigotry, etc