Nikhil Ramanathan wrote
...(although can't he jus create another account?)
Yes he can, but it will take him a few minutes to do that, and it only take a click to ban him and remove them (we will release the feature to remove him soon), so eventually he will give up.
People also do things like ban IP, but it's easy for spammer to get a new IP, they just need to restart their router - it's actually easier to get a new IP than to get another account.