In the music biz, copyright is sometimes used to prevent very specific uses of material. Recent examples include a number of musicians (or perhaps their labels

In the music biz, copyright is sometimes used to prevent very specific uses of material. Recent examples include a number of musicians (or perhaps their labels or publishing houses) denying the use of certain pieces of music at rallies for particular politician. IANAL, but my read of this is that if the content has the appropriate licence, the licence holder can withhold certain rights & access from certain groups of potential licensees. I'm loosely aware that the common open source licences are highly permissive, so probably they can't be used in this way... but presumably not all licences are like that. So, even though the work is "public", it should still be possible to enforce subsets of rights. And to take your "public square" analogy... before we had cameras everywhere, there was some expectation of "casual" privacy even in public spaces. Not everyone in the square hears everything said by everyone else in the square. The fact that digital tools make privacy breaches much easier doesn't mean it should be tolerated. (that said, I'm fairly careful what I publish online)