It is quite obvious that it is an organized bump with fake comments. It is very likely that the same person is behind all the accounts, but it does not necessarily have to be that way.
If you really want to clean it up, I suggest you report such posts to the moderator. After some time, they themselves will give up this strategy.
Also, tagging such accounts is not wrong, so I encourage you to do it. Just make sure you make valid references (probably the best in this thread) in case the OP decides to delete his topic.