Vandals dyed the Trevi fountain red in protest of some issue over the city's film festival.
Here's what the fountain usually looks like:
And, while we're talking about vacation photos from Italy, this guy makes a living doing "instant" tourist pictures, not with a Polaroid, but with a digital camera and a battery powered inkjet!
My guess is that this kind of thing is common there. Rome has lots of graffiti, much of it politically charged...
Rome's Trevi Fountain Gets Dyed Red