If the identity of the poster is known (many places allow anonymous posting or “fake” accounts) the individual can be held accountable, but the site on which the post was made is not a party in the process.

Just be sure you protect the information to avoid any identity theft claims.

I'd say attorney is your top concern, be aware of FIRPTA when selling, otherwise commercial deals are nearly identical.

For example, suppose you are considering three identical properties that rent for the same amount (yes, this is an over simplified and contrived example!).

The Rents are higher on Sustainable Living Apartments and its a win win with Tenants since while we charge $70 more the Tenant saves $100 from living in a identical Apartment with higher utility costs.

I would hate seeing hipsters buying up properties out of no where and the identity of my hood quickly disappearing. 

Unless you are a famous celebrity who has paparazzi around you, not sure why people spend all this extra money on trying to hide their identity Starting in 2024 and 2025 LLC’s with the corporate transparency act most of this goes away anyways.

My appraiser ignored a sale in an identical size and shape unit in my building that was $50K higher than his appraisal.

If you can find an identical furnace, it would be easy enough to swap it out. 

Now, under 366 days is short-term capital gains, which is taxed at marginal rates like ordinary income, so the rate is identical.