Just returned from Italy....OMG gotta move there! anyway, when we went to Trevi, NO ONE was throwing coins in, and I was a bit concerned about doing so...so we didn't...what's going on --- it is like you can no longer sit on the Spanish Steps, which I had heard about before we left??? thanks all.
We were there a few weeks ago and threw in coins without any issues. So far, coins in the fountain have always gotten me back to Rome.
I haven't read about any ban on coin-tossing, and considering the money goes to charity I doubt a ban is in place.
I was just in Rome and there are quite a few police officers posted by Trevi. They were blowing their whistles at anyone attempting to sit on the edge. However, I threw a coin in and it wasn't an issue and there were coins already in the fountain.
Rome is pretty crowded and some folks just don't know how to behave. It is my understanding that people were leaving messes, etc., which prompted the new rules about sitting on the steps and/or picnicking in certain places.
We did have an encounter in Siena. We pulled out a baguette and cheese on del Campo and in minutes we were instructed to take our food elsewhere. Apparently gelato or "snacks" is ok. Picnics are not.
Just don't toss any coins into your jet's engines as you walk up to board your flight. That will definitely not bring you good luck.
I believe the new owner of the fountain did not allow it.
Back at the beginning of the year, there was talk of an argument over who gets the money. I don't know if this has anything to do with it. Here is an article from the Daily Telegraph from January.