

Empty houses contribute more tax in some parts of the country where councils have been given permission to raise taxes on empty properties. IIRC it is up to 4x the normal rate.
Similar things could easily be rolled out where its a problem. Especially given that we already have working examples in the UK. Though its more about holiday homes, the same applies.






If it becomes a problem a compromise could be one automated post for joke comments to go under and all others are banned. You keep the funny, but its contained and easy to skip past.