According to ANSA and Il Gazzettino, a single vandal used a hammer to smash an ornate capitol (called a capitello) atop one of the columns flanking the Palazzo Ducale last Sunday around 10:30PM. The attack on the capitello depicting Moses with the 10 Commandments caused a few fragments, later recovered, to fall to the ground. The damage was confined to the arms of Moses and Christ, and the stone tablet bearing the Commandments.
The previous evening on La Giudecca, Palladio's masterpiece, Il Redentore, was victimized by someone who "repeatedly hit the statues of St. Mark and St. Francis of Assisi, severing three of their hands and leaving gashes over their bodies" according to an AP newswire account.
It's said that the authorities have not yet connected the two incidents, though with major acts of vandalism so incredibly rare in Venice, and these two attacks coming in two days on religious symbols, it can't be a coincidence.
I made "portraits" in perfect light of a couple dozen of the capitellos using a medium format camera last September. I'll check to see if the damaged capitello is among the images when I get back home (on the road today in NYC).
Updates: Donna wrote to draw my attention to reports of a third attack, this one on a bas relief of St. Peter and a statue of the Madonna at the church of San Pietro di Castello. Authorities now believe that the perp is a mentally unbalanced male around 35, who was dressed in jeans and a tee-shirt at the time of the Piazzetta attack on Sunday. They picked up a 50 year old mentally ill man in the Piazza yesterday, but later released him because he did not match the description.
Unrelated, but nearly as disturbing, in the new scrutiny that the hammer attack has brought, authorities discovered that a small stone sword from the nearby statue "Justice" disappeared at some time in the recent past, presumably the work of some demented souvenir hunter.
I was under the mistaken impression that the whole Marciana area was under the constant watch of video cameras, having read a local news story to this effect a few years ago. Apparently, this is NOT the case at all. It would appear that the Pringles cans at your local 7-11 are better surveilled and protected than some of humankind's greatest works of art.