Why is Nudity in Public Taboo?

 I want to walk in the nude
Down a busy city street
Do my everyday business
With out being discreet

I hope that I would be joined
By others with this urge
We could start a movement
To fight the prudish scourge

When we've won a victory
And you need not be attired
We could extend our remit
Privacy for sex is also not required

We could then all show our lust
To all who want to see
A public orgy might then ensue
Join in this sex for free

Why do we hide these natural functions
From all of human kind?
The animal in us must overcome
Such distortions of the mind