As ones of the comments says, you can go to https://ec.europa.eu/info/law/better-regulation/have-your-sa... and search by "invasive" to see that several responses are the same, some identified as police.

But I don't think that's evidence of a botnet. Seems more likely a conventional letter writing campaign where people are invited to paste the same response. Could easily be within the police,which is dubious, but individual police officers may have the right to respond as individuals.

Someone makes a post with a "Police" username, and all of a sudden it's a botnet.

Edit: Sorry, I didn't notice it was plural: botnets.