MO is currently being the focus of what I guess to be a single particular individual [R.T.Man](https://mathoverflow.net/users/78479/r-t-man) sporting multiple unregistered users identity (like [Eskand](https://mathoverflow.net/users/89148/eskand) or [H.night](https://mathoverflow.net/users/89001/h-night)). S/he's asking multiple *very similar and basic* questions in the topic of «matrix polynomial» and other related topological issues (like [this one](https://mathoverflow.net/questions/230371) but other very similar questions seem to appear and disappear shortly afterwards on a regular basis). I'm *fed up* voting to close and seeing again and again the same questions popping up. I'm sure moderators noticed that little game, as Todd closed single-handedly at least one post ([here](https://mathoverflow.net/questions/233709)). 

Can something be done in terms of IP filtering or is the user abusing the system by vpn-ing his/her entry here? 

More generally, what can the community do about such behavior? What should be the right route to convince him/her of stopping being such a pain in the good-will of others?