There is one person making a bunch of these today. Should the observations be flagged? It seems unfair to the observers to let it keep going.
The IDs should be flagged and you should reach out calmly to the user. If you have examples, please send them to email@example.com. Depending on the situation, the user could/should be suspended, but if they’re a serious troll, this might just encourage them. See https://www.inaturalist.org/pages/curator+guide#trolls