If it says, "Keep off the grass," then keep off the grass.

It didn't, that tape was there because a group of protesters had been living there for the past 4 months or so, so they killed the grass =(

Now that makes a lot of sense. It explains the pose, and caption a whole lot better. Some of the "Occupy Oakland" protesters did similar damage, reducing a city park into a stinking mud hole. (The city plans to re seed the grass in the Spring.) Of course there were also "Radical" factions that spray painted graffiti and smashed windows. The greatest crime in vandalism to me though was some protesters damaging a model of Oakland built in the late 1920s, which is now undergoing repair and restoration.