According to Yoshi P himself it was originally intended for us to be able to buy, sell and give away houses so I don't understand how it could be against ToS.

Letter from the Producer LIVE Part VI Q&A Summary (04/17/2013)

[0:10:11]
Q: Will it be possible to sell land deeds in the market ward or other places?

A: Yes, it will be possible. They can also be traded. Just as an example, you could give a house to that special someone in your free company as a present.