Sitting is a commodity in Venice. I think I already mentioned that the price of food goes up if you choose to eat at a table rather than standing at the bar area. Coffee will go from 1 euro to 2.5o euro before you can even bend a knee to sit. But finding a place to sit is really more of a problem....sometimes you just dont care about the price because you need to rest.
Benches are few and far between around the city. There are a few of the large squares that have 2-3 benches but they are usually filled with the elderly. I imagine this is pretty much their only way to get out during the day. So, people end up sitting on the sides of bridges (which only enhances the congestion) or storefront steps (which is why most of them have signs telling you not to do that!).
One of the last places left for 'free' sitting was off to the side of St Marks Square. There is an elevated area with a few statues of lions and an old well in the middle. All around is one step and therefore instant seating and congestion.
Well, apparently the city thought they would stop this luxurious sitting trend and placed several 'hostesses' in the area. These gals are volunteers and I think they come from the University as they know 5-7 different languages (or at least how to say 'no sitting' in 5-7 different languages). This new adventure lasted all but a few weeks before the tourists just protested and refused to get up! A prime example of strength in numbers.
The city has upped their committment and has now asked for more volunteers. They number about sixty now, and consist of pensioners, housewives, students, and professional men (but I hear there is also a youngster from a noble family and even the president of the gondoliers union). They each volunteer several hours of their time to help the 7 hostesses keep those pesky people from sitting.
My guess is that this too will be a short lived experiment and the masses of people will win again. Stay tuned.