Would it help if we did show the IP address for anonymous notes? It might make it clearer who is abusing the system and give a clear way to flag things to mods.
Wikipedia has always had a warning that editing while logged out will publish your IP and they seem to be able to make use of this for less tech savvy trolls.
To be clear: I mean for new comments, not retroactively showing an IP when the user wasn’t warned ahead of time.