Modern art?

There are 6 of these chairs in the town centre and all are like this I have often wonder why the chairs are not chairs, there are a couple of options:

1. It's modern art
2. Someone with nothing better to do has liberated the missing parts or
3. The council has removed the missing parts before someone does liberates them to use as a weapon on a Saturday night

I know which option I would prefer, however instead I think it is one of the last two. Shame that they were even options.

Dx