A B&B or not a B&B? That was the question - first for Dublin City Council and latterly for an Bord Pleanála.
The council and now the appeals board have both conferred commercial status of sorts for planning on a privately owned Temple Bar apartment which has been operating successfully as a short-let under the online global Airbnb umbrella.
So is a private home in Airbnb use a home or a commercial business? Before yesterday the answer was: "It's a private residence being used for short lets of course!"
Today that answer has changed to: "If you and your neighbours don't know then we can bring in the local planning regime to decide."
Like any truly new and (more importantly) genuinely disruptive concept - it was only a matter of time before vested and injured parties started to complain, and regulations started to impinge on the Airbnb party.
Airbnb landed among us with a bang - it came from nowhere - and instantly transformed our world.
It has revolutionised both global travel and the earning power of ordinary homeowners.
Overnight, every residence, warehouse, farmhouse, henhouse, outhouse and doghouse (not to mention tree house) became a potential short let earner.
On the other hand, tourists have also been empowered by the smart phone availability of accommodation which is increasingly within their control, genuinely vernacular and generally much cheaper than hotels.
The Airbnb impact in Ireland, where tourism is strong, was always going to be greater than in other countries and thousands have become involved in letting spaces.
The losers are the hotel and regular B&B sectors which have lost business; and renters who are increasingly finding it tough to source rooms in private houses because they are increasingly being Airbnb'ed.
So first came the decision to tax Airbnb earnings at normal rates, now comes the stipulation that frequent Airbnb usage might entail planning permission - as determined by the local authority. Gradually we are defining an Airbnb premises under a commercial regimen.
Next, expect the health and safety brigade looking for fire escape points and perhaps disabled access.
And if your back room is deemed to be a "business" rather than a bit of pin money, then comes commercial rates, insurance requirements and eventually fully commercial tax rates.
So from Airbnb right back to, erm ... B&B anybody?