I can't speak for the mods, but I suspect the issue is more that they don't want the presence of police to have a chilling effect on speech. Police are very often at the sharp end of structural violence in any country.
However, cancelling police accounts may create a false sense of security. The police can still read your posts. They can still subpoena your mods. However, at least they're preventing from stirring up trouble.
my experience from moderating a forum globally with popular ravers in the 90s/00s is discouraging overt cops works in the short term but (unsurprisingly) they switch to detective methods to glean info, often co-operating with journalists and agencies (often across borders), and it was still up to "normal" users not to blatantly incriminate themselves.
OTOH US corporate socnets welcome cops as "free moderators" so officers get a sense of entitlement to these spaces..
PS: that should have read "/other/ agencies" - eg: someone boasts in English about selling drugs online, detectives of the Gendarmerie of France see the post, and notify Police Scotland where the poster happens to be based (things like this have definitely happened, and all of that can be done without alerting the moderators or site admins as its merely making use of information that got posted on the public areas of the forum)
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